It's hard to save the world while wondering whether you're still human, but Jason1 may be just the right software for the job anyway. He's about to find out. Stranded in the computers of a derelict space station, unknown to the world, lives the first community of human-based software, or softlife. But Jason1, one of the few who used to be flesh-and-blood, doubts that this empty existence really qualifies as life. On the other hand, Iooi, a young native softlife, considers her kind an evolutionary step beyond biology, and three-dimensional space an annoying abstraction. A spaceship arrives at the space station, and the two of them stow away in its computer, hoping to establish ties with the rest of humankind while somehow tolerating each other. But the ship's crew is clearly hiding something, despite the efforts of Jason1 and some old human associates to pry it from them. And the world's first faster-than-light spaceship, lost since the wreck of the space station, has returned, and is acting very strangely. These minor mysteries coalesce into major threats, pitting the softlife against unexpected enemies they may be uniquely qualified to fight. Softlife and biological life must work together to save both of their worlds and, just maybe, learn to appreciate the humanity in each other and themselves.