Planet Killer by Ges Seger and Kevin Grazier

Characters and situations originally appeared in The Once and Future War by Ges Seger

10 OCTOBER 2191

MSV PROCYON

250 LIGHT-YEARS FROM THE COALSACK

"XO, we're not doing anything for a day or two anyway," Lieutenant-Commodore Bob Keith said as he and Executive Officer Kevin O'Byrne strode into the Officer's Wardroom, "Why should it matter how Science is mapping this star system?"

"Because they could be doing it a whole lot better," Kevin snapped.

Bob ignored Kevin's complaint temporarily in order to attend to a more immediately urgent matter. "Coffee?"

"Please. Leaded and black." Kevin snagged a table next to the forward window and stared at the (filtered) G0V star two astronomical units off Procyon's bow while Bob went to the coffee machines. On paper, Procyon could have traveled the 650 light-years from Mars to the Coalsack in a little over 100 days. Actual practice was another matter, especially when this was the first time anyone had ever attempted sustained faster than light travel across the Galaxy without benefit of a wormhole network. The Chief Engineer wanted complete, periodic, and frequent inspections of the stardrives - a sensible precaution, with the closest drydock nearly 400 light-years behind them and only enough spares onboard to rebuild both drives twice. The Astrogation team required complete, periodic, and frequent calibration checks of the nav platform - also a sensible precaution, since everyone onboard wished to return home at some point. The mission rules for both the outbound and return transits, therefore, required Procyon to stop in a star system roughly every ten parsecs to accomplish both tasks.

And that, Kevin thought morosely, is why we're sitting around a star in the middle of nowhere twiddling our thumbs. Why can't people just live a little...

"Here you go," Bob said, then he sat down himself.

"Thanks."

"So, XO, enlighten me on your proposal for planetary detection." Bob sipped his mocha before continuing dryly, "I expect this will be good."

"It is. Rerig a detonation laser for broadband EMP, then set it off. Three hours, four tops, you have position and doppler on everything in system. At least everything important."

Bob took another sip from his mocha and stared at Kevin over the top rims of his glasses. "You think every problem can be solved by the indiscriminate use of nuclear weapons, don't you?"

"Well, it's better than what Science is doing right now." Kevin O'Byrne, Procyon's second in command, was both aggressive and creative, sometimes at the same time. An excess of patience, however, was not one of his virtues.

"Faster you mean, not better," Bob corrected.

"A full-spectrum eight octant scan is rough enough without having the ship's computer tied up recalibrating the nav platforms."

"Could be worse, XO."

Kevin took the bait. "How so?"

"Somebody could be shooting at us while we're doing this."

Kevin smiled. "Point taken."

"Which brings us to my biggest problem with your plan." Another sip of mocha, and Bob continued, "With only 100 warshots per tube, we can't be popping off detonation lasers like cheap fireworks. Especially since we don't know if we'll run into Malzurkians."

However enthusiastic Kevin had been with his innovative proposal for using Procyon's armament to advance science, he couldn't argue with Bob's logic. To date, Mankind's only encounter with an alien race had taken place in 2178 when the Malzurkians had opened a wormhole near Jupiter and then attempted to destroy all human civilization in the Solar System. Humanity had been too busy fighting for its survival to bother finding out where the other end had opened.

Kevin sighed and slumped back in his chair. "You're right."

Bob took a long pull off his mocha and asked, "You know what your problem is, XO? You're bored."

"And what, exactly, was your first clue, sir?"

Bob snorted in humor at Kevin's dig and answered, "We're farther away from home than anyone's ever BEEN before, and instead of enjoying Creation, you want to do performance art with our main weaponry..."

JEDI, Procyon's artificial intelligence, interrupted the conversation at that moment. "Captain, Dr. Davies wishes to speak to you."

"Put her through."

The table repeater stopped being an electronic menu and displayed Dr. Pamela Davies down in the main science lab. "Captain, you can tell Mr. O'Byrne where he can stick his nukes. We've found planets."

"He's right here with me. Tell him yourself."

Kevin attempted to steer the conversation back on topic. "How many planets?"

"Two so far. A jovian at roughly 3 AU, and a terrestrial at 1.2."

"That's the outer edge of the Goldilocks Zone for this star, isn't it?"

"It is within its habitable zone, yes." Pamela subtly emphasized the words "habitable zone" to indicate exactly how she felt about O'Byrne's cavalier astrobiology nomenclature. "Captain, we've taken spectra from both planets, and something's not right in this system."

"Elaborate on 'not right'."

Pamela took a deep breath. "Okay. Starting with the gas giant, it's got a fairly standard atmosphere to a first approximation. When you look at it closer, there's a very strong helium-3 line."

"Your point? All gas giants have helium-3. Mars used to mine tons of the stuff from Jupiter when the Cislunars shut down all the regolith processors..."

"No, captain, you don't understand. The amount of helium-3 required to generate this spectral response is orders of magnitude beyond anything Jupiter has. It's not ... natural."

Bob and Kevin looked at each other, then back at the repeater. "Helium-3 is a decay product of tritium," Bob speculated out loud.

"That just shoves the problem back one level," Kevin offered. "How did that much tritium get in its atmosphere to begin with?"

"Much as it pains me, Captain, I have to agree with Mr. O'Byrne. We may want to wait on that problem because of the inner planet. Its spectrum looks an oxygen-nitrogen atmosphere, diagnostic that this was an inhabited planet - plant life at the very least. Still there are anomalies that we can't resolve from our current position."

"If you're asking to move closer, consider the request approved. Download the planetary state vectors to Lt. DeMarco so she can start on a system ephemeris. We'll let you know when we're in range."

"Thank you, sir," and Pamela killed the connection.

"Battle stations before we approach?" Kevin asked as he and Bob stood up.

Bob nodded. "Still bored, XO?"

Kevin smiled as he turned for the hatch. "Maybe next time I'll be careful what I wish for. Maybe."

"Minus three gradient in five, four, three, downwarping ... NOW," Carmen Sanchez called out from Helm as she smoothly brought Procyon sublight 200,000 kilometers trailing and sunward of the inner planet.

Kevin swept a practiced eye across the threat board in Combat Information. "No targets, no active tracking," he announced.

Bob relaxed at his station. "Stand down from general quarters, maintain yellow alert. Science Center, your ship."

"Thank you captain," Pamela acknowledged. Orders now flew rapidly between Science and Helm as Carmen had to position Procyon to unmask various sensors during their approach. Drones shot out of Procyon's missile tubes, and the ship's tactical crew in CIC directed them into appropriate orbits around the approaching planet.

"CIC to Bridge. I've got a good visual off the forward cameras."

"Pipe it up, XO," Bob ordered.

The main viewscreen jumped, and the expanding image of the inner planet began to fill it. Bob's stomach turned as he saw not the expected white and blue of an Earth-like planet, but a sickly brown shroud of clouds.

After a long moment, Carmen offered, "Doesn't it sort of look like Mars before terraformation?"

"No, Ms. Sanchez," Bob said, "Mars looked cleaner. Bridge to Science."

"Can we get back to you, Captain? We're a little busy right now."

At the start of the mission, she would have told me to make it quick. I've made progress... "Any better luck on atmospheric composition from here?"

"Much better. We're getting lots of NOX species ... nitric acid... No ozone, which is surprising for the amount of oxygen in the atmosphere. Plenty of ionizing radiation present, consistent with radioisotopes of carbon, nitrogen, and oxygen still in suspension."

Many more questions crowded into Bob's mind, but he squelched them all ruthlessly. They're busy. Let them do their jobs... "Thanks, Ms. Davies. Keep me posted, Bridge out."

"The quick way of describing the inner planet's atmosphere," Pamela started in Main Briefing hours later, "would be 'radioactive smog.'"

"Like twentieth century California?" Kevin offered helpfully.

Before Pamela could follow up her withering stare with a supporting comment, Bob interjected absently, "No, that was just plain smog."

"Captain?"

Bob started as if from a daydream. When did the cloud layer become radioactive?

Pamela looked to her left and nodded to Dr. Mathews, who answered, "Our drones have taken in situ samples, and we've already run 'em through the mass spec. What we've gleaned from the isotope fractions suggests the event took place sometime between 500 and 1,000 years ago. Without a good handle on the intensity of the initial exposure, we can't pin it down any closer."

"There was also an awful lot of UV-induced chemical reactions going on either simultaneous with, or just prior to, the radiation event. We have no idea what the starting atmospheric mix was before things started happening."

"So what was the event," Carmen asked. "Global nuclear war?"

Dr. Mathews shook his head. "The isotope ratios are all wrong. We'd be seeing residuals for fission products, fusion products, silicon, and other lithophile elements in the atmosphere as well."

"And in orbit," Chief Engineer Alex Duncan added. "If you can launch a ballistic missile, it's not a big leap to putting a payload into orbit. Where are the derelict satellites?"

"You're assuming our hypothetical culture developed in the same manner that ours did," Bob interrupted. "Until we get some more data points, that's not an assumption I'm comfortable making."

"What if they didn't do it to themselves?" Kevin asked.

There was a pregnant pause before Carmen voiced the subject which had already sprung to minds of all the military in the briefing room. "Malzurkians?"

"People. Time out," Bob said forcefully. Looking at Pamela, he continued, "Unless the Science Team has something else to report, we have yet to see any evidence there was sentient life on this planet, advanced or otherwise. It is useless to speculate who did what to whom when we don't even know if there was a victim."

"Hypothetically speaking, sir," Kevin argued. "During the war the Malzurkians used enhanced radiation weapons to clear the Mangala Valley beachhead."

"Then there's a quick way to settle this," Bob said, "Dr. Mathews. Assume a planet-wide bombardment using enhanced radiation weapons. Is the measured radiation spectrum from the atmosphere consistent with this hypothesis?"

"No."

"Is it consistent with any lesser usage of enhanced radiation weaponry?"

"No."

"What would be consistent with our measurements?"

"I'll take this one," Pamela said. "A supernova within ten parsecs could in theory account for all the observed damage in this system."

"Like Nova Orionis?" Kevin asked. The death of the star formerly known as Betelgeuse had been a spectacular learning experience for two generations of human astronomers, and the radiation pulse was still fifteen light-years from the Solar System.

"It came to a lot of our minds when we looked at the inner planet," Dr. Mathews said.

Carmen looked over at Pamela, a quizzical expression on his face. "Permission to ask a potentially embarrassing question."

"I'm not military, Ms. Sanchez, you need not ask permission."

"Which star exploded?"

There was a long silence as the scientists looked at each other helplessly.

"Good question," Bob mused. "From what I recall of my astronomy history, none have ever been recorded in this particular area."

"Exactly," Carmen said. "Any star going supernova within 400 light years of home should have been one of the brightest stars in our sky before exploding. Alpha and Gamma Crucis were still there when we passed them, and we still see Beta Crucis and Beta Centauri. That's all the known candidate stars between Sol and the Coalsack."

Kevin chimed in, "All that is predicated upon the idea that it was a Type II supernova, of course."

Carmen looked at Kevin quizzically, then over at Pamela. "There's more than one type of supernova?"

Dr. Mathews explained, "Indeed. Type I supernovae, for instance, occur in binary pairs - when a white dwarf is in a close orbit around a larger star. If the stars are close enough, the dwarf can accrete material from the companion star, until the pressure of the added matter overcomes the electron degeneracy pressure supporting it. The resulting implosion initiates a violent runaway fusion reaction and subsequent explosion. It usually blows the white dwarf apart, but in some cases can actually recur cyclically."

"But regardless, we still should have seen something. Right?" Carmen asked persistently.

Pamela turned to Bob and asked, "Do you need an answer right now?"

"No."

"Well, we need to mine what data we have and build computer models to tell you what happened here."

"Do you have all the data you need?"

"Are we operating under a time limit?"

"That's what I'm about to find out, Doctor. Ms. Sanchez, nav platform status?"

"Calibration's done. We're ready for the next leg."

"Mr. Duncan?"

"Starboard drive is secured and charging. We'll be ready to answer bells in three hours."

"I see no further reason we need to remain in system, then."

Pamela was now visibly annoyed. "Captain, I don't like unanswered questions. This whole system is an unanswered question."

"And perhaps someday, someone else will be out this way and take a year or two to nose around some more to solve it." Unintentionally, Bob's normally placid bass voice became tinged with iron as he continued, "The Coalsack is still 250 light-years ahead of us. Let's not be so excited that we lose focus on our primary mission."

Pamela looked down at the table. "Sorry, captain."

"Then let's get buttoned up and ready to go. Dismissed."

14 OCTOBER 2191

239 LIGHT-YEARS FROM THE COALSACK

The blast shield was down over the panoramic window in the officer's wardroom, as it usually was while Procyon was traveling faster than light. Lieutenant Kendra "Heater" Jackson contemplated this as she looked for an open table and said sarcastically, "Another day flying blind into the unknown."

Lieutenant Nathan "Cato" Perry rolled his eyes as he caught up with her. "You know what looking at FTL-induced aberration does to some people, or have you forgotten what happened to Ensign Varanov two days out of Alpha Centauri?"

"It was the only chess game I've ever seen him lose. This one?"

"Yeah." They both sat down at a table next to the window and Cato continued, "He lost because he was too busy reversing the polarity of his nutrient flow all over his queenside pawns."

"You didn't have to make him sit down so he was facing the window."

"Yes, I did. I wanted to win."

Heater frowned judgmentally at Cato, causing him to add defensively, "It's called 'situational awareness'."

There was a snort of humor from the next table over. Heater wheeled around to vent her sarcasm on a more personal target, only to end up face to face with a thoroughly-amused Bob Keith.

"Uh, sir!"

"I'll have to remember that trick. I'm not a very good chess player."

"Care to join us, sir?" Cato blurted.

Bob shrugged his shoulders, put his Bible on the table next to him, and stood up enough to turn his chair around. "Sure."

Heater stood up. "Lieutenant Jackson. I pilot Remora 3."

Cato joined her. "Lieutenant Perry. I'm the WESO for Remora 3."

"Ah," Bob said, pointing at Cato. "You find it, classify it, and jam it. Then Lieutenant Jackson kills it."

"It's a symbiotic relationship, sir," Heater acknowledged.

Bob laughed as he shook their hands. With nearly four hundred military and civilian personnel on board, he hadn't come close to greeting everyone currently assigned to Procyon personally. After sitting back down, he asked, "You've got face time with the ship's CO. Anything on your minds?"

"As a matter of fact..." Cato blurted. "Why did the Martian Space Force send a top-of-the-line battleship on its maiden voyage to the Coalsack?"

Heater rolled her eyes. Cato was very good at his job, but in most social settings he had difficulty suppressing his inner geek.

"Easy," Bob answered, "Because it was there."

Heater couldn't help herself. "Oh, you're kidding me. You're what Cato here is going to turn into in twenty years."

Bob's eyebrow raised.

"Sir."

It was now Cato's turn to be annoyed. "Hey!"

Bob raised a hand and halted both of them. "Early in Procyon's design process, I specced out two separate designs. One was a fast battleship, and the other was optimized for long-range galactic exploration. You have no idea how surprised I was when both specs turned out to be nearly identical. As for our destination, a scientific advisory panel was given a choice between the Pleaides and the Coalsack as potential destinations for this mission. The panel, almost unanimously, chose the Coalsack."

"But the Coalsack is 200 light years farther away," Cato said plaintively.

"Distance was not a mission selection criterion. Scientific merit was, and the Coalsack was simply ... more interesting ... than the Pleaides."

Heater considered a comment concerning the military merit of either destination but wisely left it unsaid. It didn't matter anyway, as something on Bob's wrist started beeping. He looked at it, made a face, and said, "Physical Training time. So that, boys and girls, concludes today's history lesson."

Cato stood up with Bob. "A pleasure, sir."

Heater also stood. "Sir."

After Bob had strode out of the wardroom, Cato said, "So that's why we're going to the Coalsack."

Heater looked at the blast shield over the forward window. "Yeah, but we still can't see where we're going."

17 OCTOBER 2191

230 LIGHT-YEARS FROM THE COALSACK

The planets were much easier to find at the next stop. Procyon dropped sublight half a second ahead of schedule when it hit the superjovian's minus three gradient just before the K0 subgiant's minus three gradient. After that excitement, it was a simple matter of scanning the plane described by both gravititation vectors to find the planet responsible.

"Beautiful system," Carmen said as Procyon leisurely approached the gas giant. The planet itself had just enough methane in its atmosphere to add a bluish tinge to its white- and rust-colored cloud belts. The space around it was lit with multiple rings, two terrestrial-planet-sized moons, several smaller icy satellites, and dozens of icy "rocks".

Bob looked at the main viewscreen, then did a double-take. "JEDI, zoom on the second moon to the left."

The screen blurred, then stabilized. Ugly brown clouds roiled across the surface of the moon.

Kevin caught the significance immediately. "Woah. Deja vu."

"Exactly, XO. Bridge to Science."

"If it's about the gas giant, we've noticed it and we're already on it," Pamela snapped. The uproar down in the main science lab could clearly be heard on the bridge end of the connection.

The entire bridge crew turned to face Bob. Uh-oh...

It was Kevin that broke the 'Oh, Crap' moment. "Let me guess. The gas giant has the same whopping huge helium-3 line in its spectrum that the one in the last system had, right?"

Pamela flinched almost imperceptibly, relaxed, squared her shoulders, and started, "The commander is right about the presence of helium-3 in the jovian's atmosphere, even if his use of scientific nomenclature leaves much to be desired. The gas giant also has a strong radiation spectrum consistent with carbon-14 decay as well. That would be similarly consistent with the methane we detected on our way in." There was a slight pause before she continued, "Did you have something you wanted to report?"

"Um, yes. You might want your crew to take a look at the large moons when you get a chance. Their atmospheres may look familiar. Bridge out." After the connection died, he turned to Kevin and with a raised eyebrow asked simply, "Whopping huge?"

"I panicked."

"Given the situation, XO, you're allowed. I want this ship on yellow alert two minutes ago. Equip all Remoras with deep recon packages, I want two in space at all times on a six-hour rotation. Nothing moves in this system without us knowing about it first, understood?"

"Yes, sir." After Kevin relayed orders to the appropriate people, he turned back to Bob and said, "I thought you didn't believe what we saw in the previous system was caused by enemy action."

"I wasn't convinced that it was caused by Malzurkians, XO. To be honest, I'm still not convinced it's Malzurkians, even after seeing this system."

"Well, if it wasn't Malzurkians, then..." Carmen trailed off.

Bob finished the thought grimly, "Then who? Someone who could crush the Malzurkians like a bug."

18 OCTOBER 2191

230 LIGHT-YEARS FROM THE COALSACK

"Remora Three, DSO. Docking clamps cleared and retracted. Confirm independent. Good hunting..." The Docking Signal Officer gave final instructions, and an editorial comment, to the departing Remora, "...and when I say 'good hunting', I mean I hope you find nothing."

"Roger that, DSO," Heater chuckled, "Tom Servo, departing." She pulsed the Remora's underside RCS thrusters to separate from Procyon, then spun the ship around to its assigned patrol heading and smoothly brought the main engines online.

When they were docked, Procyon's four Remoras appeared to be mere streamlined extensions of her hull. Unlike their oceanic counterparts, these Remoras had much sharper teeth. They had an impressive assortment of weapons and, given the current situation, Heater was not afraid to use any of them. Something about this star system had their command staff rattled, and it was their job to find out what it was.

"Gotta agree with the DSO today," Cato chimed in from the right-hand seat. Cato was the Remora's WESO, the Weapons/Electronics Systems Officer. After his initial scan of the threat board, he continued, "Yo Heater, we got scads of moons here. Why do the planets and moons with air get all the attention?"

Cato got on Heater's nerves at times. Great, it's gonna be one of those patrols today... "If you want to scan the ice moons, there are plenty of 'em. Knock yourself out."

Cato turned the visible light camera towards a moon just entering into eclipse. "Aye sir. If nothing else, this one'll be worthy of blowing up, framing, and hanging on the wardroom..." His words trailed off as the image appeared on his screen.

"What?" Heater asked impatiently.

"Wait one." Cato tended to chatter while he worked. "I can't believe what I think I see. The detector on this camera is sensitive to light a lot fainter than what the eye can see, but if I stretch the image..."

On Cato's monitor, the computer-processed image clearly revealed a faint haze surrounding the moon. "Heater, about face! This moon has an atmosphere. It's tenuous, but it's there."

"Thought you had a bug up your behind about things with atmospheres," Heater chided as she brought Tom Servo about.

"You don't understand," Cato said, no longer in his normal "playful banter" mode. "Moons like this aren't massive enough to have atmospheres, and when they do they don't have 'em for long. This means that something heated the snot out of this moon, and recently. Could have been a meteoroid strike, a stellar flare...."

"...weapons fire," interrupted Heater.

"...weapons fire," Cato confirmed. "I want to get multispectral images of the moon, I bet I know what that gas is. Mapping IR bands to RGB, and..."

"And?"

"Frak me!" blurted Lt. Perry.

"Frak? You've been hanging around O'Byrne too much," Heater said. "Whatcha got?"

"See for yourself. I'm sending the scan to your monitor."

Heater saw the image of the moon on her viewscreen. Exactly half of the moon appeared gray-white in the false color image, the other half a brilliant blue - as if somebody had sawed both a pool cue ball and 2 ball in half, and glued one half of each ball together.

"What do you say now, Heater?"

"Frak me!"

"Even today," Dr. Davies lectured in Main Briefing hours later, "scientists disagree on the 'correct' material state of glass. At room temperature it has no crystalline structure and will flow over time. On the other hand it's brittle, will support shear, and is certainly very hard. Amorphous ice is similar in this respect: it's hard, but lacks a crystalline structure. What we have here," she said gesturing to the viewscreen, "is a moon where one hemisphere is amorphous ice, the other is ordinary crystalline ice."

Bob didn't like where this was heading. "So how do you turn one form to the other?"

"I'm getting to that," offered Davies, "but bear with me a bit longer. The Remora crew first noticed a rarified atmosphere around the fifth moon. The WESO speculated, correctly I might add, that the atmosphere was atomic oxygen. A large pulse of energy, like gamma rays for instance, would vaporize some of the ice, and melt much of the rest..." Davies searched for a word, then just made one up, "... of the 'pulseward' side. The vaporized ice would be photodissociated into hydrogen and oxygen by the UV radiation of this planet's star. The lighter hydrogen escapes the system rapidly; the oxygen hangs around a bit longer. That explains the tenuous atmosphere. We're far from this planet's star; it's cold out here. The ice that melted to liquid refroze almost instantaneously, yielding the amorphous ice hemisphere."

"Talk about being two-faced," Kevin quipped.

Bob, on the same page, added, "Too bad the name Janus is already taken at Saturn. But why this ice moon?"

"Oh it wasn't just one ice moon," Davies said as she changed the display on the viewscreen, "all of the icy moons in this system are altered in this fashion." On the holoviewer now was a computer-generated graphic of the planet and its system of moons, each moon displayed as a fusion of two very different halves.

"Madre Dios," Carmen murmured.

"In fact, it gets even better," Davies continued, "JEDI, bring up simulation Davies 13-bravo." The onscreen image was replaced by a similar image, but with only 8 moons. "We determined the state vectors - positions and velocities - for each of the moons, as well as their spin orientations. We then eliminated moons with chaotic orbits or spin states, and then JEDI integrated their trajectories backwards. JEDI, run simulation 20 years per second."

The simulated two-faced moons orbited backwards on the holoviewer. After half a minute, Kevin asked impatiently, "And we're looking for...?"

Dr. Davies, in her best military impersonation, said, "Wait for it.... There! JEDI, pause."

The simulation stopped. The amorphous ice hemispheres of all the moons were facing the same direction.

"Okay, that's interesting," Kevin replied with only a hint of nervousness in his voice.

Bob leaned forward and adjusted his glasses to try to read the frame index of the simulation. "How long ago was this, doctor?"

"About one thousand years ago."

"Wasn't that when the damage happened in the previous star system?" Carmen asked.

"Roughly, yes," Pamela answered.

There was a long, silent pause. Bob finally said, "Two systems twenty light years apart receive the same types of damage at about the same time. Dr. Davies, please tell me it's a coincidence. Lie to me if you have to."

Pamela shrugged her shoulders helplessly. "A supernova or hypernova would explain the evidence perfectly, but we're right back to the question Commander Sanchez posed the last time we discussed this. Which star exploded?"

"There's always the 'invincible alien armada' theory," Kevin offered none too helpfully.

"Show me how damage on this scale can be done to an entire star system by an invincible alien armada and I'll consider it," Bob shot back waspishly.

Bob and Kevin glared at each other across the table for a moment before Bob continued, "Ms. Sanchez, nav platform status?"

"Nominal. Recalibration should be done in six hours."

"Good. Mr. Duncan, drive status?"

"Port drive check should be complete in twenty-four hours, barring the unforeseeable."

"So we're here at least another day. XO, can we keep the Remoras on deep recon deployment for that long?"

"Yes. I'll need to borrow all our relief helmsmen so I can rotate my dedicated crews into rest breaks - with Ms. Sanchez's permission?"

Carmen nodded, and Kevin continued, "If I have to, I'll take one out myself and stand patrol."

"Do what it takes, Mr. O'Byrne. Dismissed."

2 NOVEMBER 2191

185 LIGHT-YEARS FROM THE COALSACK

"We really have to stop meeting like this," Pamela said as both senior scientists and Procyon's senior officers filed into Main Briefing. "Even my crew is getting jumpy."

"At least it wasn't radioactive planetesimals in chaotic orbits this time," Kevin replied. Their previous maintenance stop had been particularly harrowing.

"Yes, did the science staff ever figure out what happened?" Bob asked, "They've had JEDI running some pretty extensive sims all week."

"Staff agrees that the belt was not the result of a planetary breakup. What happened, happened to a previously-stable planetesimal belt. Even twentieth century planetary scientists could have understood the theory, if not the sheer scale, of application we witnessed."

"That's a relief," Bob said as he sat down. Almost as an afterthought, he added, "Sort of."

"How's that, sir?" Carmen asked, "You've still got something out there capable of kicking very large rocks around like soccer balls."

"Anything that could convert a planet into a planetesimal belt has to deal with its gravitational binding energy. For the Earth, the amount of energy works out to about a week's worth of energy from the entire Sun..."

"How do you KNOW stuff like that off the top of your head?" Pamela interrupted with disbelief, "Some government program you can't talk about?"

Bob allowed a slight smile to cross his lips. "Actually, it was a rather memorable homework problem in undergraduate physics. Fortunately, it looks like we won't have to worry about that particular scenario."

"But we still have a very persistent unanswered question to deal with," Kevin said darkly.

"Unfortunately, true. JEDI, display current system ephemeris."

The holoviewer engaged and a simulation of the current star system hovered over the table. Pamela took over from there. "Three gas giants in the outer system, all with the same anomalous helium-3 line in their atmospheric spectrum. There are four inner planets, numbers 2 and 3 have atmospheres. Number 2 has the same radioactive smog we've been observing in other planets with large nitrogen concentrations. Number 3 resembles Mars after phase one terraformation - carbon dioxide and water vapor - and also shows radioactivity consistent with the presence of carbon-14."

After Bob finished his sip of mocha, he asked, "Any ideas?"

Pamela looked nervous before answering, "I really want this to be due to natural causes, but the evidence just doesn't add up that way. We've got four systems over a distance of sixty parsecs showing the exact same pattern of damage, and no obvious mechanism that we can find."

Dr. Mathews speculated, "What if a star pulled an Eta Carinae on us - well what we're expecting from Eta Carinae anyway - and went hypernova? A big enough hypernova doesn't even leave behind a black hole." He then added, "No smoking gun."

Pamela corrected, "While you're absolutely correct about a hypernova's potential to destroy even its own core, I'm not sure that helps us here. Let's use your example, Eta Carinae, as our poster child. It underwent a giant eruption that was witnessed on Earth in 1843, and which was nearly as bright as a supernova itself."

Dr. Mathews agreed, "Right, it's called a false supernova."

"In a few years," Pamela continued for the non-astronomers in the room, "Eta Carinae produced almost as much visible light as a supernova explosion, but it survived - leaving behind two huge lobes of expanding matter. Since then we've observed several false supernova. They are considered precursors, and are often followed shortly after by a full-blown stellar explosion. In every case something resembling a nebula has been left behind: 'smoke', from the hypernova's gun."

As everbody in the room digested that information, Pamela finished, "Finally, before anybody says it, the internal structure and mass of all the candidate stars in the vicinity - the Crucis supergiants and Beta Centauri - have been known for centuries. None of them come close to matching Eta Carinae and we see no evidence of eruptions of any kind."

"Further, let's add that we've also clearly established that, there is no historical evidence from Earth records, right?" Bob asked. After an awkward pause, he continued the thought, "As I said last month, I don't remember any supernova - Type I, Type II, hyper, or false - taking place in this particular area of the galaxy in the past millennium."

There was a long, awkward pause. Finally, Bob squared his shoulders and said, "Okay, I think we all need to be thinking in terms of someone rather than something. What are we up against?"

Dr. Mathews looked at Pamela, who nodded for him to go ahead. "First off, captain, you'll need to look at what damage has been caused. The 'radioactive smog' we've been observing is the result of ultraviolet - or even higher energy - radiation bombarding atmospheric nitrogen and inducing various chemical reactions. If we assume gamma rays, that would also account for the lack of ozone we've been seeing in planets with significant oxygen concentrations."

"What about the radiation?"

"Electrons, protons, high-velocity atomic nuclei, and a whole zoo of other sub-atomic particles." Mathews paused for a second, then continued slowly, "I've just described a nasty solar flare. If it's big enough, the tritium it would generate in a gas giant's atmosphere would explain the helium-3 lines we've been observing."

"So our nasty boys can trigger really big stellar flares," Kevin mused. "Is that possible?"

"Not with our technology base. If the Malzurkians had it, they would have used it on us in the war."

Bob drummed his fingers nervously on the table, looking absently at the system ephemeris as he pondered everything he had just heard. Finally, he said, "We will proceed with our mission as ordered. However, we all need to be prepared to abort and get this information back home."

"Abort our mission to the Coalsack?" Pamela asked.

"Mission orders allow the ship commander to abort the primary mission in the event humanity is in jeopardy. That particular section was written with Malzurkians in mind, but the Space Force gave me some latitude in how I choose to interpret, or exercise, it." Looking across the room, he added, "We're not there yet, people, but we're getting awfully close."

5 NOVEMBER 2191

170 LIGHT-YEARS FROM THE COALSACK

Bob was working over a particularly difficult section of Rachmaninoff's Second Concerto on his piano when he felt a tremor in his sustainer pedal - the same tremor he always felt when Procyon dropped sublight. Knocking the piano bench over in his haste, he was on his feet and out the door of his cabin at a dead run before the first battle station klaxons sounded throughout the ship. Seconds later, he had sprinted up the steps to the command deck and was running into the bridge.

"Watch officer, Captain has the conn," Carmen snapped while working controls at Helm.

"Bridge aye."

"This is the Captain I have the conn, status?" Bob gasped as he fell into his station and rapidly scanned his repeaters.

"We dropped across a minus four gradient one minute ago. I'm generating a vector tangential to the gravity well."

"What minus four gradient? We're five light-years from the nearest star!"

"Good question. I wanted to set EMCON Bravo as well, but we've got a radiation problem and I had to rig plasma screens instead."

When you don't know what you're up against, try not to be seen. Never thought she was paying attention in combat sims... Bob thought. "Good, fast work, Ms. Sanchez. Bridge to CIC."

"CIC, O'Byrne," Kevin looked as rattled as Bob felt.

"How long can the screens hold this load?"

"We're in no immediate danger, but I wouldn't want to stay in this position too long. The radiation is also partially blinding our sensors, and we can't get a good look around us until we do something about that."

"Thank you, XO, bridge out. Ms. Sanchez, maintain course, ahead full."

"Ahead full, aye sir."

Between the minus four and minus three gradients of a gravity well, Procyon's drive performance was significantly degraded. Given that this was the difference between 2,000 times lightspeed and twice lightspeed, the difference was currently meaningless. In just over a minute, the aurora that was shimmering across the plasma screens faded into nothingness.

"Okay, that's a lot better," Kevin reported from CIC. "You can stop while we take a look around."

"Ms. Sanchez, all stop."

"Aye, sir."

"Okay," Kevin reported, "We've got a gravity well source at zero-two negative by zero nine one, range six point one five AU. Appears to be several solar masses, with no obvious visual source. You might want Commander Duncan to take a look at some of these potential space readings, because I can't believe the strength of this magnetic field. Before you ask, systems passed a quick diagnostic."

"Feed it to Engineering. Bridge to Engineering."

"Engineering, Commander Duncan."

"I need you to take a look at the telemetry CIC is forwarding you."

Alex looked off camera for a moment, suppressed a curse, then said, "You're running a sim up there, right?"

"Negative. The source is currently six AU off our starboard beam."

"You're not thinking about getting any closer, I hope. A magnetic field this strong could pull water molecules apart from several hundred kilometers away."

That's a visual I didn't need right now... "Unless we've got a real compelling reason, I was planning on keeping us right where we are now. Bridge out."

"I heard that, and it sounds like good advice," Kevin added from the CIC repeater. "We're relaying everything to Main Science."

"Do we need to remain at battle stations?"

"No, but Yellow Alert goes without speaking."

Bob smiled. "Understood. Set condition yellow, XO. Bridge out."

Six hours later, a swirling disk hovered over the table in Main Briefing. Ghostly lobes shot out of the top and bottom along the disk's rotation axis. Irrationally, Bob wanted to duck out of the way of the hologram as he looked at it.

"The object 6 AU away is confirmed to be a black hole," Pamela started, "We've been able to refine Commander O'Byrne's quick measurement of several solar masses to approximately 6.115 solar masses."

"If it's a black hole, what about that magnetic field? I thought black holes weren't supposed to have them," Kevin said.

"Think, commander. You've got very rapidly-moving plasma around the event horizon, which is the next best thing to an electric current loop. Of course you're going to have a magnetic field." Pamela turned to address the rest of the briefing. "The density and composition of the accretion disk does give us an important clue as to this system's age. After analysis, we conclude that this system can't be much over..." she paused for effect, "...one thousand years old."

"Now there's a suspiciously familiar number..." Bob murmured.

"That thought occurred to a lot of us, too."

"But doesn't it take a supernova to form a black hole?" Carmen asked.

"So did that thought."

"Great. So our nasties have now graduated from sterilizing planets to generating black holes?" Kevin said.

"Hold on. I had my staff do some data mining through our archives over the past several hours, and we may have found how to generate this system without blowing up a star. This is a mechanism first proposed in the late twentieth/early twenty-first century to explain some of the intense gamma ray events being detected by the Vela satellites. The Velas were launched to detect gamma ray signatures from space-based nuclear weapons test ban violations."

"It's a gamma burster?" Kevin said incredulously.

"It's a gamma burster," Pamela confirmed. "It's something we've observed for hundreds of years, but always in distant galaxies. It never really occurred to anyone that they could happen in ours."

"So does a gamma burster explain what we've been seeing the past month?" Bob asked.

She manipulated some controls, and the hologram above the table changed to show two neutron stars slowly spiraling toward each other. "It does. We start with neutron stars in mutual orbit."

"Why aren't their orbits stable?" Carmen asked, noting the decaying orbits.

"Two reasons." Almost unconsciously, Pamela got up and slowly paced around the table as she spoke, almost as if lecturing a class. "First, gravitational wave emissions. Mostly because the progenitor neutron stars are so fast and close to each other. Now watch what happens when they approach each other's tidal limits... Their accretion disks interact, creating an intermittent drag..."

In the simulation, the approaching neutron stars suddenly shredded apart along their mutual orbits. The debris rapidly spiraled into the system's center of gravity, then two intense beams of radiation shot out along the system's rotational axis. "In the process of forming the final black hole, the excess energy is funneled out along their orbital angular momentum vector ... which becomes the black hole's spin axis," Pamela explained matter-of-factly. "The leading edge of the jet will consist of an intense burst of gamma rays, followed very shortly by highly-relativistic particle radiation. With sufficient plasma densities, it is possible the beams may be self-focusing over interstellar distances. You're basically cramming the energy of an entire supernova into two very narrow opposing jets."

Bob's mouth slowly opened. "Where would the beams have been aimed?"

"When we originally dropped sublight, we were very nearly looking down the rotational axis of the accretion disk," Carmen trailed off, then looked up and said. "JEDI, display current astrogation plot. Include this location plus the location of our last four maintenance stops."

The display swam and projected the requested data. Bob now took over. "JEDI, assume a gamma-ray generating event of the type previously modeled by Dr. Davies has taken place. Given the current alignment of this system's rotation axis relative to the galaxy, plot where the radiation jet would fall on this chart."

The radiation beam shot out from the newly-formed black hole and speared through the galaxy. One by one, the lobe approached each of the previous four systems Procyon had visited over the past month.

One by one, it missed each one.

Carmen muttered an inarticulate and vaguely Spanish-sounding curse under her breath. "Reminds me of my Masters' thesis research," Bob said, clearly disappointed by the outcome of the simulation.

Kevin's face, however, showed he didn't share everyone else's mood. Bob noticed this and said, "Yes, XO?"

Kevin finally found the words he was looking for. Looking at the ceiling, he asked, "JEDI, are we using current positions for the highlighted stars?"

"Yes."

"Bingo," Kevin said with overly-savage triumph.

"Oh, my," Bob breathed. He understood what Kevin was getting at immediately.

"What? What's wrong?" Pamela asked. She was uncharacteristically slow on the uptake.

"We never corrected the sim for one thousand years of proper motion. We're looking at the stars where they were when we visited them, not where they were when the event happened." Kevin leaned back in his chair and finished smugly, "Never send an AI to do a man's work."

A wave of recognition slowly broke over the briefing room. "Mr. O'Byrne, would you mind doing the honors?" Bob asked.

"With pleasure. JEDI, edit sim. For the four stars highlighted, change their galactic positions to where they were at the time of the gamma ray event and allow the stars to move based on their recorded proper motion and galactic orbit."

"Done," JEDI said almost immediately. Only those with astronomy backgrounds knew the amount of calculation hidden in the slight gap between command and response.

"Reset simulation to starting positions and go," Kevin commanded.

Again, the radiation lobe shot out from the newly-formed black hole and speared through the galaxy. One by one, each of the four systems Procyon had visited was tagged by the jet.

Everyone stared at the holo before Bob said with a deliberately-exaggerated Tharsis backcountry drawl, "Yup. There's your problem..."

After the laughter died down, Pamela continued, "Let's not relax just yet," Dr. Mathews interjected. "Is that thing pointed anywhere toward Sol?"

Carmen eyeballed the holo and replied, "Not a problem. It's in plane but fifteen degrees antispinward. The only reason we came across the aftereffects was that we were cutting across the direct bearing between Sol and the Coalsack to head for Beta Crucis."

"Which would explain why we never saw anything from home space," Kevin added.

Bob turned to Pamela and asked, "Do we need to stay around here any more?"

"No. Case closed."

"Good. Ms. Sanchez, have Lt. DeMarco plot a minimum-time course to the minus four gradient and resume our previous course from there..." As people stood up to leave Bob added, "...but before you go.... I need to say something. You all have no idea how relieved I am right now. As a man of both science and faith, I will also admit to being ... embarrassed. We've all been guilty of tunnel vision, ignoring an obvious answer for what we've witnessed, instead seeing Malzurkians, or worse, laying in wait behind every moon and planet. Perhaps it's understandable, given our recent history, that we're still a little shell-shocked. The irony in this case is that, consciously or otherwise, we were overlooking a force far more frightening than any alien race could ever be. This was never the action of any alien race - it was an act of God."

Bob paused to let that thought sink in, then continued, "A wise man once noted that WE are all made of stardust. Every atom in your body was once in a star, and many of those were created in the cataclysm of supernova billions of years ago. But as we venture out into space, surrounding ourselves with increasingly more sophisticated technology, we've tended to forget how fragile our bodies, our race, and our planets truly are. The Universe is a very inhospitable place; and as we continue on our mission we would be wise to reflect upon that, and how rare and blessed is our existence. Dismissed."

6 NOVEMBER 2191

35 LIGHT-YEARS FROM BETA CRUCIS

Kevin entered the bridge to stand evening watch and found Bob absently fiddling with one of his station's repeaters. "What are you doing, sir?"

"Evening, XO. Just playing with Dr. Davies' gamma ray burster sim."

"Still? It's six light-years behind us. Let go of the past."

"You deal with it in your way, XO. I'll deal with it in mine." Bob levered himself up from his usual slouch and sat up straighter. "The ship is normal in all aspects. The watch was completely boring. We're holding course and speed for system entry during midwatch tomorrow."

"Boring," Kevin mused. "Haven't been able to say that for a while."

"I know. I got so bored I seriously considered bending mission rules, foregoing the next stop, and ordering a course change to Beta Crucis from here."

"I wouldn't, sir. Our crew needs the downtime after the past month."

"Hence why I didn't do it."

"So, still being bored, you then resorted to randomly sterilizing thousands of star systems throughout the galaxy by playing with Science's GRB sim."

"Somebody's having issues about letting go," Bob teased. He swiveled the repeater toward Kevin and continued, "I was actually playing with the initial conditions of the neutron star collision to see what would happen with the beams."

"Anything interesting?"

"As a matter of fact, yes. Did you know that a difference of two kilometers in lateral separation during initial orbital capture yanks the beam fifteen degrees to spinward?"

"So?"

"On a direct heading to the Solar System?" Bob prompted further.

After a long pause, Kevin simply said, "Ah."

"There but for two kilometers and the grace of God goes Humanity. With that humbling thought, I bid you good night." Bob stood, stretched, and yawned before continuing, "This is the Captain, the Executive Officer has the conn."

"Bridge aye," the crew chorused.

"This is the Executive Officer, I have the conn," and Kevin sat down at the captain's station.

"Bridge aye."

Kevin ran some quick status checks across the station repeaters as he got himself settled in the captain's chair. He then looked at the simulation Bob had been running for a long moment. Curiosity fought with "letting go" and the more practical impulse to clear the repeater.

Curiosity won.

Afterword:

Comments from Kevin Grazier: When I was asked to consider writing a science fiction story that also served as an astronomy lesson, my thoughts instantly bifurcated with both paths eventually re-converging to create "Planet Killer". I had recently had lunch with Phil Plait, author of Death from the Skies: These are the Ways the World Will End. One of the topics we discussed, because wholesale death and carnage always makes a Denny's lunch more palatable, was what would happen to planet Earth were we in one of the polar "beams" of a nearby gamma ray burster. "Nearby", in this case, means "anywhere within the Milky Way Galaxy". In short, life on Earth would be largely exterminated in less time than it took us to finish our lunch: a mass extinction that would put to shame anything that has happened in Earth's history to date. As we discussed the gory details, I couldn't help but think that the scenario was so dramatic that Hollywood has overlooked the ultimate in disaster flicks.

At the same time, my mind also raced to "I have got to include Ges!" Ges Seger and I met as undergraduates at Purdue University, and had written several things together over the years. Most notably, we wrote a script for the series Star Trek: Voyager that resulted in an invitation for us to pitch story lines at the Hart Building - the Star Trek offices at Paramount Studios. We work very synergistically and often come up with ideas and scenarios together that are better than what either of us come up with independently. I also really quite enjoyed the characters from his novel, The Once and Future War, and thought that it would be a whole lot of fun to let the crew of Procyon tell us the tale of a murder mystery of planetary proportions.

Comments from Ges Seger: Kevin and I have been friends since we were in the same residence hall at Purdue University, and writing partners for almost as long. This generally means I sometimes have access to writing opportunities of which I would not normally be aware. Planet Killer was one of those opportunities.

About the same time Kevin approached me for contributing to the book The Science of Dune, he mentioned he had been invited to contribute to an anthology that would consist of science fiction stories based on specific concepts in modern astronomy and astrophysics. We kicked some ideas around for a couple of emails before he made the inspired simultaneous choice of both concept and story seed - an astronomical "murder mystery" which would serve as either a prequel or sequel to The Once and Future War.

As I read that email I realized that of the two possibilities (prequel or sequel), the prequel made far more sense. The backstory of the Martian starship Procyon, her first crew, and her first mission were very well-developed in my fictional universe thanks to an aborted attempt to write a novel on it in the early 1990's. As I realized this, I got this vivid mental image of Bob Keith looking at a holotank showing the path of the gamma ray burster's beam and saying, "Yep, there's your problem."

That's when the Muse hit. Hard.

The first draft of Planet Killer literally wrote itself in three hours, spread over seven nights hammering away at a laptop between shuttling children back and forth to dance class. I was a bit afraid I hadn't left Kevin much to do, but those fears proved groundless as we co-wrote/co-edited the second draft together and added a lot more material. Kevin and I just seem to mesh as a writing team in ways that I can't explain easily, and that came through in spades as the final version of the story got hammered into the form you see now.

And truth to tell? It was kind of fun having him play in my universe with my characters and ships. No pressure, Kevin, but I hope we can do it again.

Copyright Kevin Grazier and Ges Seger