Buck, Wilma, and Twiki set off into deep space aboard the Searcher, a starship on a mission to find the lost tribes of Earth -- humans who fled to the stars after a nuclear holocaust that all but destroyed the planet. The Searcher encounters a severely-damaged spacecraft with one survivor, who tells them of a savage attack by a bird-man named Hawk. Searcher sets course for the planet where it is believed Hawk lives, and Buck soon becomes involved in a desperate battle of wits and piloting skills with Hawk. Hawk's mate, who was a passenger in Hawk's ship, is mortally wounded in the battle and Buck and Hawk form a shaky alliance to seek medical aid for her. Eventually, Hawk joins the crew of the Searcher, looking for others of his kind.

Hawk's first mission among the humans is to join Buck, Wilma, and Dr. Goodfellow in escorting Ambassador Duvoe to a peace conference that could avert a terrible galactic war. Crisis strikes as their shuttle passes through an electric storm and crashes in the desert. With contact with Searcher impossible, the party must travel by foot to Oasis, encountering savage mutants and a mischievous gnome named ODX.

Hawk's first mission among the humans is to join Buck, Wilma, and Dr. Goodfellow in escorting Ambassador Duvoe to a peace conference that could avert a terrible galactic war. Crisis strikes as their shuttle passes through an electric storm and crashes in the desert. With contact with Searcher impossible, the party must travel by foot to Oasis, encountering savage mutants and a mischievous gnome named ODX.

Buck finds himself entrusted with a bizarre glowing green box when he and Hawk find an old man near death on a remote planet. Back on the Searcher, the box creates a series of bizarre images in the minds of the crew members. In reality, the box has taken control of the Searcher and sent it at fantastic speeds toward an unknown destination.

The Saurians plot to destroy the Searcher and start a galactic war by infiltrating the starship and a space station in human disguise. Only Buck, who has contracted a strange virus, is able to see the true form of the Saurians, but no one believes him. When the Suarians realize that Buck is a threat to them, he becomes the target of their assassination attempts.

The Searcher rescues a gold-skinned boy from an escape capsule in an asteroid field. When the ship collides with one of the asteroids, the boy displays his powers of molecular alteration by rescuing Admiral Asimov from beneath a fallen girder. The boy assures the crew of the Searcher that, with the help of his companion, who is on a nearby planet, he can dislodge the ship from the asteroid. But when Buck and Hawk go to the planet to get the companion, they find that he is being held captive by a man who wants to use the boy's powers for his own greedy purposes.

Buck, Wilma, and Hawk are confronted with a bizarre riddle on an alien planet they are exploring for crystals to power the Searcher. Part of the riddle is the connection between a young woman and an eerie, mummy-like creature they encounter on the planet. Meanwhile, on the Searcher, the android Crichton believes he has discovered the link -- one that is crucial to the success of their mission.

Buck and Twiki come across the survivors of a failed colony, a young widow and her son. The woman tells Buck that the other colonists all fled the planet as the result of a plague. Buck is confused by the woman's refusal to leave the planet despite being repeatedly being menaced by a goat-man named Pangor; but he soon discovers the truth about the plague when he contracts it and begins to turn into a goat-man himself.

Buck is ordered to explore a derelict spaceship that the Searcher encounters, and finds it filled with solar bombs and crewed by seven little men. They are escorted back to the Searcher and Admiral Asimov takes their ship in tow to a place where the bombs can be safely detonated. Assuming the little men can cause no real harm, Buck places them in the care of Wilma; but the little men have never seen a woman before and are intent on finding out what all of the "funny little bumps" are.

Buck, Wilma, and Hawk explore a strange planet and come across the wreckage of a spacecraft and its lone survivor. He is taken back to the Searcher by Wilma, while Buck and Hawk continue to explore. After some unexplained happenings on the planet, they return to the Searcher, where they find that everyone has undergone personality changes -- becoming the opposite of their real selves. Buck soon learns that he can not even trust Wilma and Hawk to help him solve the mystery of what has happened.

An ancient videotape is discovered that proves that Buck was involved in the nuclear holocaust that nearly destroyed the Earth hundreds of years before. Commissioner Bergstrom convenes a war crimes trial aboard the Searcher and, if Buck is found guilty, faces a death sentence. In a desperate attempt to clear himself, Buck agrees to another mind probe, but his memories seem to confirm the charges.

Buck and Hawk are sent to pick up the survivors of a planetary disaster and transport them to a new home. Before departing, Buck rescues a young woman from a group of Dorian thugs. Later, while enroute to the planet, the Searcher is attacked by a Dorian craft, which demands that the woman be returned for the murder of a warlord's son. As the Dorians persist and subject the Searcher to a severe pounding, the refugees begin to rebel, insisting that the woman be turned over. Eventually, Buck discovers that truth about the woman and the startling reason why the Dorians always wear what at first appear to be merely ceremonial face masks.