AD 2118. Humanity has colonised the Moon, Mars, Ceres and Europa. Captain Ellisa Shann commands Khidr, a search and rescue ship with a crew of twenty-five, tasked to assist the vast commercial freighters that supply the different solar system colonies.

Shann has no legs and has taken to life in zero-g partly as a result. She is a talented tactician who has a tendency to take too much on her own shoulders. Now, while on a regular six-month patrol through the solar system, Khidr picks up a distress call from the freighter Hercules…