Velocity Wrachant and the crew of the Susan Calvin have been working in Pirian Space for three years, doing adjunct work for the Pirian fleet. When they are offered a mission in Republic Space, they know this is their chance to be taken in as full members of the fleet. And the job looks safe enough: they are to rescue some Pirian fleet members out of contract labor, while also learning what they can about local insurgencies.

The planet they are sent to, Durbin, is in Republic-held space. But it's at the fringes of that space, in the seldom patrolled area known as The Deep. Velocity takes the mission, hoping to get in and out without attracting the attention of the powerful, and hostile, Combines. Once they reach the planet, however, they learn that the political situation there is far more complicated-and dangerous-than they expected.