Buck escorts Miss Cosmos, a woman as close to genetically perfect as has yet been discovered, on a cruise. But a pair of thieves has also boarded, and they intend to kidnap Miss Cosmos and dissect her into nice, marketable bits of genetic material. They make one attempt that nearly succeeds, revealing that one of them possesses dangerous abilities that will test Buck's defensive and security planning skills.

Buck has been moping about, pining for the Earth he once knew and can never know again. So when Twiki suggests a surprise birthday party, Dr. Huer and Wilma agree. Their problem then becomes how to get Buck out of his apartment while they set it up. That proves easy enough when the Security Directorate sends a courier for Dr. Huer's itinerary: they ask Buck to escort her back to the Directorate, which is concerned about a possible threat to Huer's life. But the threat is very real and the source of it a very bitter and dangerous man, who has been cooped up in prison underground for nearly fifteen years - and blames Huer for it!