The Floating Zombie

"The Taking of AT1: Before AT1 had ground down the slipway unchristened—rightly, said seamen, for it would be a ship with no soul—it had been dubbed 'Zombie'. That sinister name would stick & prove its accuracy. AT1 was a robot-ship, a ship with no crew, only a tiny security force of three men & a woman. 'Invulnerable,' said its inventors, 'foolproof'. But it was neither—not if one of the four security guards was an insane, ruthless killer. & if the greatest & most powerful & self-contained nuclear reactor in the world fell into the hands of such a person, the whole world was in peril!"