Nightside City, tourist playground of the planet Epimetheus, is doomed — the planet isn't as tide-locked as the settlers thought, and in a few years its rotation will move the city onto the dayside, where the sun's radiation will render it uninhabitable.

Private investigator Carlisle Hsing had escaped to the neighboring planet Prometheus and had no intention of ever going back, but then she was hired to find out who had attempted to assassinate Yoshio Nakada, billionaire head of the Nakada clan and CEO of Nakada Enterprises.

The crime had taken place on Prometheus, but Hsing's investigation took her back to Nightside City, and uncovered far more than a simple assassination attempt.