WE ARE THE CAT by Carl Frederick

Carl Frederick is a theoretical physicist, at least theoretically. After a post-doc at NASA and a stint at Cornell University, he left theoretical astrophysics and his first love, quantum relativity theory, in favor of hi-tech industry. The inventor of the first commercial digital modem, he now works as the chief scientist of a small company doing AI software. He has two more-or-less grown children and shares his house with a pet robot. For recreation, Carl fences épée, learns languages, and plays the bagpipes. He lives in rural Ithaca, New York. (He tells us rural is good if you play the bagpipes.) A graduate of the Odyssey Writers Workshop, his work has primarily appeared in Analog. Carl also has an interactive novel on his website—www.dark zoo.net—. You can click on the story to change the points of view and to expose sub-plots. (While there, you can also hear a nifty translation of the fruit-fly genome to music.)

Over the din of falling rocks crashing against the sheer walls of the shaft, Paul heard a scream of pain.

“God damn it,” Paul shouted, “I said don’t look up.” He squeezed himself into a cleft in the flare-out chamber. And cowering there, just meters from the entrance pit, he hoped that none of the rocks raining down onto his hard hat would be massive enough to break his neck.

He turned his head slightly, slewing the beam of his miner’s lamp to illuminate Alex. At the same moment, the beam from Alex’s lamp moved as well and Paul squinted against the sudden brilliance. Had they been under the sunlit sky and not in the blackness of a cave, they would be looking each other in the eye.

Again, Paul heard a sound of pain, this time a moan, and swung his head and beam to the source: the third spelunker, Conrad Frith. Almost buried in the tumble of rocks, Conrad had slumped to the cave floor and seemed unconscious. His hard hat sat askew on his head, and the electric miner’s lamp was dark.

As abruptly as it had started, the pummeling of rocks subsided and the roar of the limestone avalanche, amplified by the resonances of the caverns, went silent. When his hearing had adjusted to the eerie quiet, Paul could hear only the dripping water from the tips of the stalactites.

After a few moments, when he felt confident that no more rocks would fall, Paul pushed himself out of the small cleft in the cave wall and surveyed the damage.

He moved toward Alex, just a few meters away. “Are you okay?”

Alex took a step away from the wall that he’d squeezed against, but then let himself slide down to a sitting position. His face, which had registered fear, now showed a mix of relief and pain. He winced as he massaged his left leg just below the knee.

“Jeez,” he said. “Hurts like hell.” He explored the limb with both hands. “But I don’t think it’s broken.” He wiggled his shoulder blades and let out a breath through pursed lips. “But other than that, yeah, I guess I’m okay.”

Again, Paul heard the sound of falling rocks, but this time just a gentle clatter. He directed his lamp to the far side of the entrance chamber and saw Conrad freeing himself from the debris. “Conrad,” Paul called out. “You okay?”

“Yeah. I think so.”

Clambering over the rock-strewn cave floor, Paul made his way over. “No you’re not.” He shone his light strong into Conrad’s face. “There’s blood pouring down your forehead.”

Paul called over his shoulder, “Alex, there’s a first aid kit in the drag pack. If you can walk, would you get it?”

“Yeah, just a sec,” Alex called back.

Paul removed Conrad’s hard hat and, in the beam of the laser diode headlamp, he saw Conrad’s Germanic-blond hair glisten a dark crimson.

“Oh shit,” said Paul under his breath.

“Jeez!” cried Alex, and Paul turned at the sound.

Alex tugged at the drag-pack line; the rope drew taut, one end vanishing under a pile of small boulders. “Buried,” said Alex, “and even if we could dig it out, it’ll probably be crushed flat.”

“Damn it.” Paul whisked off his gloves and zipped down his one-piece coveralls. He worked his way out of the elastic-cuffed sleeves, took off his shirt, and passed it to Conrad. “Here. Press this against your head.”

Shivering in the damp cold, Paul fumbled with the zipper and struggled to regain the warmth and security of coveralls and gloves.

“Okay,” said Paul, catching his breath. He took back his shirt and, though impeded by his thick gloves, managed to fashion something of a turban. He secured it on Conrad’s head with the sleeves. “Score one for Boy Scout training.”

Although a section of cloth covering Conrad’s head was turning red, Paul let out a sigh of relief as he noted that the blood flow seemed to be staunched.

“Thanks, um…” said Conrad. He looked pained for a moment. “Thanks, Paul.”

“What’s the matter?” asked Paul. “Does it hurt?”

“No. It’s not that.” Conrad looked away, avoiding Paul’s gaze. “It’s just that for a moment, I forgot your name.” He shook his head. “And that scares me a little.”

“I wouldn’t worry about it. You probably have a slight concussion.”

“Concussion, yeah.” Conrad sounded relieved.

“I hope this cave has another entrance,” said Alex, softly, from behind.

“It doesn’t,” said Paul, still preoccupied with Conrad’s condition.

“You’re sure?” It sounded more like a plea than a question.

“Never absolutely certain about anything,” said Paul. “I’m a quantum theorist.”

“Boy, you’re a great help,” said Alex. “Thank you, Dr. Heisenberg.”

Paul swiveled around, his beam making a quick circle around the cave walls. Alex had spoken with his usual flippancy, but a tremor in his voice gave him away.

“Well, it’s your fault,” said Paul, smiling. “What we get for taking an undergraduate along on a grad-student outing.”

“Oh no,” said Alex.

“Just kidding.”

“It’s not that.” Alex pointed. Where there had been an entranceway to the vertical pit, a mountain of glistening rocks stood against the cave wall. “There’s no way we can dig our way through that.”

Paul suppressed a gasp and fought down a sudden panic. He was the cave leader and he knew he had to display calmness. “Theoretically, that should not have happened.”

“Jeez. Theoreticians,” said Alex, shaking his head and sending an oscillating beam of illumination against the cave wall.

“Switch off your light,” said Paul. “Let’s see if we can see any daylight.”

Paul and Alex switched off their lamps; Conrad’s was already dark.

“Nothing,” said Alex.

“Keep your light off,” said Paul. “Give our eyes time to adapt.”

Paul struggled to see gradations of darkness, but there was no light. He had the notion that he’d suddenly gone blind and that there was no one in the dark with him. Listening hard for human breathing, he heard nothing but the occasional sound of dripping water.

Why do I do this, he wondered. But he knew the answer. Despite the cerebral rush he got from doing physics, he seemed to need a matching visceral high—an adrenaline rush. And boy, am I ever getting that now. God, I’m scared shitless.

“Alex?” he said after what seemed a lifetime, but could only have been a few seconds.

“Yeah?”

“Okay, lights on.” Paul flipped the switch and felt warmed, even by the cold, blue-white illumination of the laser diodes.

But Alex’s lamp stayed dark.

“Damn,” said Alex. “Now my light’s broken.” He pounded on his head-mounted lamp, then took off his hard hat and flipped the switch a couple of times. Still no light. “Jeez. You’d think the Outdoor Club might invest in some new equipment.”

Paul sucked in a breath. Now they had only one light source between them. Paul shivered with a mental image of total darkness. As he turned to look at Alex, he realized he was moving his head slowly—as if a fragile treasure were balanced on his hard hat. Damn it. We should all go back to using carbide lamps.

Conrad, meanwhile, absently toying with his hard hat, started as the lamp blinked on. “Hey,” he said, “‘and there was light.’”

“Thank God,” said Paul. He looked over to where the drag-pack was buried, keenly aware of the loss not only of the first aid kit, but also of the crucially important alternate sources of light.

“Keep the lights switched on,” he said. “Batteries should last a week, so if we don’t mess with the switches, at least we’ll have light. And it’s a live cave so we don’t have to worry about drinking water.”

“A week,” Alex mumbled under his breath. He nervously worked the switch on his dead lamp. “How long do you think it’ll be before someone rescues us?”

“Don’t know,” said Paul. “When you got the gate key, how long did you say we’d be caving?”

Alex stopped playing with the switch, but he didn’t answer.

“Alex?”

“No one was home, so I just took the key off the hook.”

“Did you leave a note?” Paul spoke softly, trying to keep his voice steady.

“No, but when he gets home, he’ll see the key’s missing.”

“God damn it,” said Conrad, sitting, his back against the cave wall with his hard hat resting on a knee. He moved the hat to direct the beam into Alex’s face. “For all we know, the guy’s vacationing in New Zealand. And…” The beam wavered, casting Alex’s silhouette flickering against the far wall.

“What’s wrong?” said Paul.

“I forgot where New Zealand is.”

Alex gave Paul a puzzled look. “It’s near Australia,” he said. “Anyway, someone’s bound to see the van, not to mention Quantum.”

“I wouldn’t count on it,” said Paul. “Only the owner and other cavers use that road.” Paul looked down at his hands and willed them to stop shaking.

Conrad closed his eyes. “The road is roughly north-south and we’re at latitude 41.5,” he said, “and his leash reaches to the stream.” Conrad slapped a hand against the cave floor four or five times, the glove making squishing sounds against the thin layer of mud. “So, at this time of year, considering the length of his leash, where it’s tied to the car, and the path of the sun in the sky, Quantum should always be able to find some shade in the shadow of the van.”

“Jeez.” Alex slapped the wet rock of the cave wall. “We’re trapped in a cave and all you can do is calculate if your dog’s going to be comfortable.”

Conrad opened his eyes, and his eyes were wild. “It took me a lot longer than it should have.” He opened his mouth as if he were going to say something, then bit his lip.

“In the absence of mass,” he blurted out, suddenly, “space doesn’t become flat, it becomes undefined—stochastic.”

“What?” said Paul.

Alex wrinkled his nose.

“If there’s no mass, we don’t need space,” said Conrad.

Paul saw Conrad’s hand begin to shake. “What the hell are you talking about?”

“It’s right, isn’t it?” Conrad spoke with none of his usual assurance.

“You okay?” said Paul.

Conrad put on his hard hat, then winced. “Ouch.” He adjusted the hat, then stood. “I’m scared, guys. I’m losing my memory. I can almost feel it vanishing.”

Alex and Paul stared at him.

“I’ve got to keep exercising my memory.” Conrad leaned his head back against the cave wall. “I’ve got to talk about stuff.”

“There are other things we could talk about beside physics,” said Alex.

“I’m a physicist,” said Conrad. “There’s nothing else. It’s what I am.”

Paul, despite himself, laughed. “Come on, Conrad. Don’t you think you’re exaggerating a little?”

“No.” Conrad looked away, into the blackness of the cave. “I come from a poor family.” He spoke barely above a whisper. “We never had anything.”

He turned and looked directly at Paul. His expression, Paul realized, was not the usual mixture of cool reserve and intense concentration. Conrad’s face showed a real emotion—anguish. And his eyes, watery-bright in the beam of Paul’s lamp, gleamed like tiny, blue bicycle reflectors.

“All I have is what I know and how well I can think.” Conrad stroked his cheek, leaving a smudge against his nose. “I don’t smoke. I don’t drink. I won’t do anything that could impair my mind. And now this.” He walked over and sat facing Alex and Paul. “Please. I don’t know what else to do.”

“Okay,” said Paul. “Nothing much we can do anyway—except wait.” Paul suddenly wished he weren’t the leader; then he wouldn’t have to hide being scared.

“We could look for another entrance,” said Alex. “There might be one.”

“There might,” said Conrad, his voice calm, like his normal self—but his eyes gave him away.

Paul worried. Conrad always had a sharp memory. “Conrad,” he said with forced calmness. “We’ve done this cave a lot together. It’s a simple cave. We’ve never seen even the hint of an alternate entrance.”

“You see? I’m losing it!” Conrad shouted. His voice, harsh, reverberated against the walls. He jumped up and then pounded a gloved fist against the wall. “So, in the case of the two slit experiment,” he said with a strained steadiness, “even if we measure which slit the particle went through, the interference pattern is not affected as long as the measurement is not remembered.”

“What?” said Alex. “That’s not true. Any measurement of which slit the electron goes through, destroys the pattern.”

Paul smiled. He didn’t know how therapeutic this conversation was for Conrad, but it was certainly taking Alex’s mind off their problems.

“That’s the establishment view,” said Conrad. “But it’s wrong. Look. An electron is charged. It has a field, and when it goes through a slit, the atoms making up the walls of the slit feel the effect of the field. So those atoms are making the measurement. But they don’t ‘remember’ the measurement. It’s a question of memory.” Conrad’s voice wavered. “…of memory.”

“It’s all right, Conrad,” said Paul, “I can’t be certain there’s not another entrance.”

“Blessed are the uncertain,” said Alex, “for maybe they shall see Heisenberg.”

Paul shot him a look, then turned to see Conrad ambling off further into the cave. “Conrad, wait.” He scrambled to his feet. Alex stood as well.

Conrad stopped and looked back.

“So, what you’re saying is,” said Paul, humoring his friend, and Conrad very much seemed to need humoring, “is that only if a measurement is remembered and then communicated to the rest of the world, will the interference pattern go away.”

“Precisely. And the argument holds for Schröedinger’s Cat as well.”

“That’s nonsense,” said Alex. “Memory is not a physics concept.”

Paul resisted the urge to kick Alex in the shins.

“Okay, a flip-flop,” said Conrad. “Imagine the latch being set if the slit atoms detect the electron.”

“A flip-flop isn’t a physics concept either,” said Alex.

Paul idly wondered which of Alex’s shins was the bruised one.

Conrad turned and began strolling toward a sliver-like passage dimly seen against the far wall. Paul, despite himself, couldn’t help thinking about the physics. He followed after Conrad. Alex shuffled along as well.

“All right,” said Conrad. “Forget about flip-flops. Think about time-reversal.”

Paul stopped. “Wait. Are you saying that if you time reverse an experiment, and the time-reversal makes sense, then it is not a measurement?”

“Yes.” Conrad continued walking. “I think so. I think that’s what I think. If there’s no arrow of time, then…. “Conrad picked up his pace.

“Where are you going?” asked Alex.

“To look for another entrance.”

“Come on, Conrad,” said Paul. “Let’s sit down. Conserve strength and all that. We can talk physics.” He plopped down on a smooth-topped calcite formation and indicated that Alex and Conrad do the same. Alex sat, but Conrad kept walking.

“Hey, Conrad,” said Alex. “Sit down. I thought you wanted to talk physics.”

Conrad stopped for a moment, started to turn, then paused and continued walking toward the far passage. “Yes,” he said, “I did. But I’m forgetting basic ideas. I remember saying things about them but I don’t remember why.”

“Please, Conrad,” said Alex. “I’d like to ask you about some physics stuff that bothers me.”

Paul felt a new respect for the sophomore physics major. Alex was certainly trying to help.

“Look,” Alex went on. “When it really comes down to it, I don’t really even understand magnetism. How can a magnetic field go through a vacuum? It wouldn’t really be a vacuum then.”

Conrad stopped and looked back. “The world is more complicated than it seems.”

“Don’t give me that,” said Alex. “That’s just using fancier words for ‘I don’t understand it.’”

“I understand it.” Conrad sighed. “At least I did up until a few minutes ago.” He turned and continued walking.

“Sit down,” said Paul. “It’s just the effects of the concussion.”

“Maybe.” Conrad quickened his pace. “But I don’t want you to see me turn into an idiot. I don’t want you to see me unable to do physics.”

Alex started to get up, but Paul waved him to stay seated. They both watched as Conrad faded into the dark passage, his light flitting from wall to wall as he walked.

“You shouldn’t have let him go,” said Alex when all hint of Conrad’s light had disappeared.

“How do you suggest I could have stopped him? He’s not exactly the sort of person you can give orders to.” Paul clenched a fist. And I’m not about to humiliate my friend.

Alex let out a sigh. “I guess.” He looked at Paul. “But now that he’s running on write-only memory, he could get lost.”

Paul looked over at the far passage, too far away for his miner’s lamp to pull it from the darkness. “This is a simple cave—pretty linear geometry.”

He lifted his feet to rest on the formation and, knees bent, leaned forward and circled his legs with his arms. Looking down at his feet, he concentrated on the small disk of jittering brightness cast by his lamp. “But what I’m really worried about is that now we have only one light.”

“What’ll we do,” said Alex, his voice mirroring the jittery movements of Paul’s beam.

“Nothing. Just sit tight.”

“I can’t.” Alex moved his head erratically from side to side, as if he could actually see into the darkness. “I keep feeling the cave’s going to collapse and crush me.”

Paul forced a laugh. “Claustrophobia. This is your first cave. It’s normal.”

“Yeah. Thanks a lot.” Alex jumped to his feet and took a step or two forward, and then turned back “I can deal with the claustrophobia.” He sat heavily on the rock. “But I can’t stop thinking about what will happen if your light fails.”

“Yeah.” Paul closed his eyes for a moment. “Worries me, too.” He slowly got to his feet. “Okay, we’ve got to go find Conrad. I hadn’t realized till now how much I miss his light.”

Alex stood, and Paul led the way towards the sliver-like cleft. “Besides,” he said, “you’re right. What else is there to do?”

At the fissure, Alex held back, apparently with second thoughts. “That’s really narrow,” he said. “What if we get stuck?”

“It widens out after a couple of meters, but then there’s a crawlway.” Paul slid sideways into the passage. “And the secret of a crawlway is to keep your arms at your side and inch forward by pushing with your toes.”

“I’m not sure I like this,” said Alex, as he too slid into the fissure.

“Wait till you see the view at the other end.” Paul grimaced. That was a really lame thing to say.

The passage ended at a nearly circular, but very small, opening at ground level. Paul dropped to the muddy floor. “Now for this little wormhole,” he said as he wiggled into the opening.

“It won’t take us to another universe, I hope,” said Alex from behind. “You know, this is sort of spooky. What if you get stuck?”

“Unlikely. If I do, you can squirm up close to me and I’ll be able to push forward against your hard hat.”

“What if I get stuck?”

“You’re thinner than I am.” Paul panted from the exertion. “But yeah. This isn’t exactly the Lincoln Tunnel. Anyway, if you can take full breaths of air, you can be sure you won’t get stuck.” He inched forward, digging in with the toes of his boots and pushing ahead. “It’s only when a passage gets so narrow you have to take shallow breaths that things start to get dicey. Hard to talk in those passages. Makes you feel really alone.”

“I don’t like this,” said Alex.

“You’re doing fine,” said Paul. “We’re at the narrowest point now, and you’re still talking.”

The wormhole ended at a large chamber. Paul and Alex clambered out and stood.

Sweeping with his miner’s lamp, Paul saw irregular, translucent columns of pale green and pink: calcite cave formations some two meters thick. Water trickled down from the ceiling, sparkling in the beam of his lamp. Icicle-like stalactites hung from the cave roof, their colors ranging from milky whites to greens to pale blues, with occasional sprinklings of pink. The walls were wet and water-carved, revealing striations that traced the history of the cave over thousands of years.

“Pretty, isn’t it?” said Paul.

“Yeah.” Alex gawked like a tourist. Then he rubbed a gloved hand across his forehead, leaving more mud on his brow than he’d removed. “But I think it would look a lot prettier to me if I didn’t think I’d be gazing at it for the rest of my life.”

Paul chuckled—forced, but still a chuckle.

“Damn it, Paul.” Alex pounded a fist against the cave wall. “Doesn’t anything scare you?”

“I try not to let it. Besides, what’s the use?” Paul felt an instant of satisfaction. He’d been able to fool Alex; he’d been able to mask his panic.

Alex shrugged and shook his head.

“I was scared shitless on my first caving trip, too,” said Paul. “Afraid I’d panic and make an idiot of myself.”

“That’s not what I’m scared about.”

“I know.”

Alex absently snapped off a small stalactite and fiddled with it.

“Don’t do that,” said Paul. “We’ve got to protect the cave for the next visitors.”

Alex laughed, his voice echoing hollow in the hard-walled chamber. “Yeah. Next visitors.”

“We’ll be okay,” said Paul. “We may be in the cave for a while, but we’ll be okay.” He pointed toward the rear of the chamber. “Come on. Let’s find Conrad.”

Two openings, close together and fissure-like, pierced the back wall. Paul stood a few meters in front and gazed at them.

“Are you wondering which way Conrad went?” said Alex.

“It doesn’t matter.” Paul shook his head. “They both go to the same chamber. I was just thinking; it’s like a two-slit experiment.”

Alex laughed. “Yeah. If Conrad really has no memory anymore, then by his theory, he could have taken both paths.”

Paul continued gazing at the fissures.

“I’m joking,” said Alex. “Please tell me you know I’m joking.”

“Yes. I know you’re joking. I do not believe he went through both passages.” Paul paused a second or two. “But…”

“But what?” Alex stared, wide-eyed. “God, don’t tell me you’re losing it, too.”

“I was just thinking.” Paul stroked his nose and stared at the clefts in the rock wall. “I was just thinking that our situation is sort of like the Schrödinger Cat paradox.”

Alex looked up at the ceiling. “You are losing it.”

“In the Cat Paradox, the cat’s neither alive nor dead until someone opens the door to the box—until someone makes a measurement.”

“I thought there was more to it than that,” said Alex, “linear superposition of states, or quantum events, or something like that.”

“Quantum events happen all the time,” said Paul. “What makes the cat special is that it’s in a box and cut off from the rest of the world.”

“I don’t know why I’m humoring you,” said Alex. “But are you saying that we’re neither alive nor dead?”

“Just speculating,” said Paul. “In the multi-world quantum interpretation, being cut off could mean that we’re not in any well-defined world.”

“You’re saying that we are the cat?”

“Just a thought.” Paul shrugged. “Conrad believes that only memory or the act of being observed keeps a system in one world.”

“I know what world I live in,” said Alex. “I have memory.”

“Yeah,” said Paul. “But maybe Conrad doesn’t. Now, maybe there are multiple Conrads flitting between multiple worlds.” Paul kicked at a small rock, barely snapping it free from the centimeter-thick layer of mud. “But since our wave-functions interact, we’re probably forcing our Conrad to stay in our universe.”

“Okay, okay,” said Alex. “This is starting to weird me out. Let’s go find Conrad.” He walked to the left fissure and waited. Paul had to take lead; he had the only source of light.

Paul scuttled sideways into the opening. “This is roomier than the last one.”

Alex followed. “Roomy? I’d feel better if I could just walk, one foot in front of another. “Hey,” he cried out. “Something flew by my head.”

“A bat, probably.” Paul swung his head around, hitting his helmet against the wall. His light went dead. “Damn.” He flipped the switch a few times, but the lamp stayed dark. “God damn.”

“What happened?” Alex called out.

“Slammed the light and it went off.”

“I can see that.” Alex’s voice sounded sarcastic and nervous at the same time. “Turn it on.”

“I’m trying.” Paul tried working the switch—pushing the toggle forward and back, up and down.

“Paul?”

“What?”

“I can’t hear you. I can’t see you.”

Paul, still fiddling with the switch, didn’t answer.

“This is sort of scary,” said Alex.

Paul, by feel, tried to disassemble the lamp.

“Paul,” said Alex with a tremor in his voice. “Are you there?”

“Of course I’m here. Where else would I be?”

“Aren’t you a little scared?”

“Sheesh,” said Paul. “Well. I’m not exactly thrilled about the situation.” He got the lamp apart, but he dropped a battery and even if he could have seen it, he had no room to bend down and pick it up. Damn it to hell.

“Paul?”

“What?” Paul turned his frustration from the lamp to Alex. “We can’t keep playing Marco Polo forever, you know.”

“That’s a good idea,” said Alex. “Do you mind? I get nervous not knowing you’re there. So, if I say ‘Marco,’ you say ‘Polo.’ I’ll do the same for you. Humor me, okay?”

Paul shrugged in the darkness and his shoulders hit the sides of the fissure. “Yeah, fine. Polo.”

“Thanks.”

“But,” said Paul, “can’t you hear my breathing?”

“Yeah, and I hear you slithering along the rocks. But, well….”

“Well what?”

“But it’s kind of creepy.” Alex laughed, but it didn’t sound like he’d found anything funny. “And I’m never really sure it’s you.”

Paul shook his head as he reassembled the now thoroughly useless lamp. He put his hard hat back on.

“What do we do now?” said Alex.

“Keep going. We’ve got to get out of this passage and find Conrad—fast.” He started scrambling through the passage. “If Conrad were to come back looking for us and if he went through the other passage, we’d really be up the creek.”

Paul, despite all his experience spelunking, began to feel that the walls were slowly shifting—that they were coming together. He wrinkled his nose in the darkness; after all the times he’d gone caving, only now did he realize how he hated the acrid smell of wet calcite.

Bumping his knees and twisting his ankles as he went, Paul pushed forward.

“Marco.”

“Polo,” said Paul, strangely relieved at the sound of Alex’s voice.

After a minute or so of strenuous scrambling, Paul said. “Alex. Are you there?”

“Yeah. Of course I’m here. Where else would I be?” said Alex, repeating Paul’s words with some added measure of sarcasm.

“I just wanted to make sure you were okay,” said Paul.

“No. You were just too proud to say ‘Marco.’”

“Okay, okay.”

“Paul?”

“Yeah.”

“Do you think Conrad’s right when he says that without mass, space becomes undefined?”

“Yeah, could be.” Paul wondered if Alex was actually interested in physics at the moment, or just using it as a variant of “Marco.”

“Even though Einstein says it becomes flat?”

Paul laughed. “Einstein didn’t believe in quantum mechanics.”

“What about this multi-world stuff. Is this really possible?”

“It’s a real theory. In fact, some people say we’re always flitting between these parallel universes—but no one notices because they’re all extremely similar.”

“But Conrad thinks that without memory to hold us, we could wind up in a very different universe.”

“You’ll have to ask Conrad about that.” Paul hurried forward and suddenly tumbled out of the crevice. “Watch it, Alex,” he said. “We’ve come to the end of the fissure. I’m in a big chamber now.”

“Yeah,” said Alex. “I can tell by your voice.”

Paul heard him come through and stumble. “You okay?”

“Yeah. Now what? Oh my god.”

“What’s the matter?”

“Look hard over to the rear,” said Alex. “Gosh, I can’t even describe where to look in this damn blackness.”

“What are you talking about? It’s not as if there’s anything to see.”

“But there is.” Alex virtually squeaked in excitement. “At least I think there is.”

Paul quickly scanned across 180 degrees. “Probably just the effect of darkness, your brain trying to supply light.”

“Oh.” Alex sounded crestfallen. For a half-minute or so, neither spoke, but then Alex said, “Paul, try to see it. I think it’s real.”

Paul did try.

“Well?” said Alex.

“Maybe, but I’m sure it’s a mental glitch. Hey.” Paul felt a hand touch his back and then feel its way down to his arm.

“I’m going to point your arm to where I think I see it,” said Alex.

Paul let his arm be directed, and then he gasped. His arm was pointing about twenty degrees upward and in the direction of his own perception of the light.

“Well?”

“It might be real,” said Paul. “Come on. Let’s check it out. But don’t get your hopes up. It might be cave fluorescence. Never seen that in this cave, but I’ve never been fully dark-adapted before either.” Paul hurried as fast as darkness would permit. “Marco,” called Alex from behind.

“Polo. Ouch.”

“What happened?”

“I slammed into the wall. Oh my gosh. It’s coming in from a side passage and it’s real. Must be Conrad.” He waited until Alex bumped into him and then shouted, “Conrad. We’re over here.” He spoke to Alex. “Come on. Let’s go meet him. Light has never looked so good.”

“Conrad,” shouted Alex from behind.

They scrambled toward the light.

“Why doesn’t he answer?” said Alex.

“And why isn’t the light flickering?” said Paul. “I hope he’s not unconscious.”

Then they heard a distant shout. “Paul, Alex. Over here.”

Paul jerked his head around to a point downward and about thirty degrees off to the left of the light. He saw another light, this one flickering. He stopped and Alex banged into him.

“If that’s Conrad,” said Alex, “then the other light’s coming from another entrance.”

Paul called out, “Conrad, we’re coming.”

“No. Stay where you are,” came Conrad’s voice. And he sounded his usual, confident self. “I’ll come over and guide you to the entrance.”

“Okay,” Paul shouted back. He spoke softly then, almost under his breath. “I can’t believe there’s really another entrance.”

Alex laughed, a laugh of relief. “It’s because of that entrance we’re alive.”

“You know,” said Paul, his voice tentative. “Maybe not. Maybe because we’re alive, there is an exit.”

“I don’t know what you’re talking about.”

“Yeah,” said Paul, as Conrad came into seeing distance, “I’m not sure I know what I’m talking about either. Just some multi-world stuff.”

“Your light failed?” said Conrad as he came up.

“Yeah,” said Alex. “Boy are we happy to see you, and I mean ‘happy,’ and I mean, ‘see.’”

Conrad laughed. “Come on. Let’s get out of here. You’ve probably had enough cave for your first time.” He turned to Paul. “I’ve got my memory back—all of it, I think.”

“Great,” said Paul, clapping Conrad on the back. “Concussions can be serious.”

Paul knew that some of his cheerfulness was play-acting; he was thrilled to be rescued, of course, but he couldn’t shake the feeling that, in some manner, his brain had let him down. “By the way,” he said with a studied nonchalance. “How did you find the entrance?”

“It’s where it always was. I’m a little surprised you don’t remember it.” Conrad turned and strode toward the diffuse light in the distance.

Alex ran to follow, leaving Paul to bring up the rear.

Presently, they turned a bend in the passage and some thirty meters ahead, saw daylight filtering through a dense green mass of shrubs and scraggly ground vines. Paul noticed that the vines were adorned with thorns.

“Not the entrance of choice,” said Conrad, “but it works.”

Alex rushed forward, and head down, using his hard hat as a shield, burst through the tangle of greenery. The thorns ripped into Alex’s high-tech, microfiber caving coveralls, but he didn’t seem to notice.

Paul, taking advantage of the hole Alex had cleared with his body, darted through.

While Conrad more carefully made his way out of the cave, Paul tried to get his bearings. Squinting in the dizzying sun-bleached brilliance, he looked over the terrain; they weren’t actually very far from the original entrance. Paul stood basking in the familiar—the green, sunlit, craggy hills of upstate New York. He could see Conrad’s SUV parked just off the road and could even see the rubber rat Conrad used as a dashboard ornament. And Quantum, Conrad’s Belgian Shepherd, leash tied to a door handle, was sleeping, stretched-out, in the shadow of the car.

Conrad came up from behind. “Okay, let’s go home.” He jogged lightly toward the van.

“I’m sorry I acted like a kid back there,” said Alex, standing beside Paul.

“Not to worry,” said Paul, still taking in the scenery. “Lots of people, when they go through their first wild cave, feel very vulnerable—like little kids. Besides, we’re physicists. We’re supposed to act like kids.”

Paul, at a walk, started down after Conrad, stopping every so often to swat at a mosquito. After hours in the perpetual fifteen degree Celsius coolness of the cave, the summer heat felt oppressive and the humidity trapped in his cave-coveralls quickly turned to sweat.

As Paul and Alex came up to the car, Quantum, who’d been jumping about happily and licking mud off Conrad’s face, bared his teeth and growled.

“Hey.” Conrad knelt in front of his dog. “Quant, boy. These are old friends.” He looked over his shoulder. “Don’t know what’s gotten into him. He probably blames you for him being tied up here for all this time.” Conrad stood. “Or maybe he knows that we’re taking him to the Quantum Mechanic.”

“You mean the vet?” said Alex.

“Maybe you guys better ride in the back and let Quantum sit up front with me.”

“Yeah, fine,” said Paul. He glanced at Conrad’s improvised head-bandage. “You could use some mechanic work as well.”

“Naa. I’m okay.” Conrad gingerly touched his scalp. “Well, maybe if I bark a few times, the vet might take me after he finishes with Quant.”

The three cavers stripped out of their mud-encrusted coveralls, dry-washed their faces, and packed what little gear they had left into their duffels.

“Too bad about losing our drag-pack,” said Conrad.

“Better than losing our lives,” said Alex.

While Conrad untied Quantum’s leash from a rear door handle, Paul keyed in the car-lock combination. But the door didn’t open.

“Hey, Conrad. Did you change your combination?”

“No. It’s still Pi to five significant figures.”

“I keyed in 31415, and it doesn’t work,” said Paul.

“It’s 31416. Rounded.”

“But you always truncated it.”

“No I didn’t.” Conrad reached forward and keyed in the combination. “Maybe the cave-slide shook you up more than you’re letting on.”

“Maybe.”

The doors opened. Conrad plopped down in the driver’s seat and Quantum jumped in and over him, settling himself in the front passenger seat. Paul and Alex took the back.

Conrad started the engine. Because of the van’s noisy muffler, conversation was difficult.

As they drove off, Paul stared out the window and couldn’t shake the feeling that he was looking at familiar scenery from unfamiliar angles.

“Well, Alex,” Conrad shouted over the muffler roar, “you’ve just survived your first caving trip. Did you learn anything?”

Alex laughed. “Yeah. A lot of physics.”

“Oh? Like what?”

“Well,” said Alex, loudly. “In the absence of mass, space becomes undefined.”

“What?” Conrad looked in the rear view window. “That’s nonsense. Space becomes flat.”

Alex and Paul exchanged glances.

“What do you mean?” Paul asked the image in the window.

“Einstein was convinced of it and since last week’s Felixhaugen lecture, I am too.” Conrad shook his head. “Boy, that Felixhaugen is really sharp.” He locked eyes with Paul. “I saw you come late to the talk. What did you think of it?”

“What the hell are you talking about?” Paul spoke more loudly than he needed to. “And who the hell is Felixhaugen?” He stared wildly at the rear view mirror; Conrad stared back and there was no doubting the worry on his face.

“I wonder,” said Conrad, “if perhaps now you’ve lost your memory.”

Alex leaned over and whispered into Paul’s ear. “Something’s wrong here. I’m scared.”

“Yeah,” said Paul, softly, “maybe I’m scared, too.”

Quantum jerked his head around and growled at them.

“And Quant,” said Paul, under his breath, “seems not to like cats.”

Copyright © 2006 Carl Frederick