|The broadcast interview of a young computer prodigy attracts the attention of aliens aboard an interstellar trading ship. The kidnapping of Tommy (and his cat) begins an adventure among the stars, a coming of age story entangled with computers, faster-than-light travel, a dying civilization, and an ancient evil.
On board the five-thousand-meter starship, he meets a crew of humans, descended from peasants, priests, and soldiers taken from Earth a thousand years before. He soon learns that all are slaves to the seldom-seen aliens inhabiting the upper third of the ship. His first months are spent in mindless work that he later learns is meant to domesticate his ?feral? nature.
Eventually, he is introduced to the reason for his kidnapping: Tommy is expected to replace the ancient and failing computers on the ship with computers taken from Earth, beginning with the long-dead missile controller, without which the ship is defenseless. After the new missile controller, with Tommy as its operator, successfully defends the ship against attack, his ?benefactor,? one of the alien Nesu masters, directs him to replace the environmental and navigation computers. This work leads to revelations that the star drive is from still another alien group -- called the Guardians by the Nesu -- who, fifteen hundred years before, destroyed the Nesu home world and now block all scientific advancement in the local arm of the galaxy.
Tommy?s determination to return to his family expands to include returning all the human slaves to Earth, using his control of the computers that now run the ship. With the help of a Nesu mathematician, will he also find a way to free the Nesu from their enthrallment by the Guardians and protect the Earth from the fate of the Nesu home world?