Beck Garrison lives on a seastead — an archipelago of constructed platforms and old cruise ships, assembled by libertarian separatists a generation ago. She's grown up comfortable and sheltered, but starts doing odd jobs for pocket money.

To her surprise, she finds that she's the only detective that a debt slave can afford to hire to track down the woman's missing sister. When she tackles this investigation, she learns things about life on the other side of the waterline—not to mention about herself and her father—that she did not expect. And she finds out that some people will stop at nothing to protect their secrets . . .