Following the disastrous events on the fortress world of Jago, where the Imperial troops are nearly defeated by Chaos, the Tanith First are pulled back from the front line for rest and recuperation. After two years' garrison duty on Balhaut, however, lack of action is sending the Ghosts stir crazy. Against a backdrop of increasing bad behaviour and insubordination, Gaunt is secretly summoned by Guard Intelligence. They have captured a high-level Chaos officer, but their interrogation is getting nowhere; the man is refusing to speak to anyone except Gaunt. The information the prisoner holds is crucial to Imperial war effort, but will he survive to ever tell it? As a crack force of Chaos insurgents closes in for the kill, Gaunt finds himself trapped in deadly game of intrigue and murder, where no one can be trusted, and the fate of the Sabbat Worlds Crusade hangs in the balance.

While on a covert mission into the space hulk debris belts of Salvation's Reach, Gaunt, haunted by secrets from the past, and the suspected taint of Chaos itself, wonders if he can trust everyone around him.