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 . . .