"The Ultimate Weapon" is a novel, originally serialized as "Uncertainty" in Amazing Stories in 1936. "The Planeteers" is a collection of "Penton and Blake" stories, including:The Brain Stealers of Mars; The Double Minds; The Immortality Seekers; The Tenth World; The Brain Pirates.
Description:
"The Ultimate Weapon" is a novel, originally serialized as "Uncertainty" in Amazing Stories in 1936. "The Planeteers" is a collection of "Penton and Blake" stories, including:The Brain Stealers of Mars; The Double Minds; The Immortality Seekers; The Tenth World; The Brain Pirates.