Ingrid Langley is rather happy with life. Her latest books have been successful, the new novel is shpaing up well, the children are thriving, and the future is looking rosy. If only her husband, Patrick Gillard, a man of mercurial moods at the best of times, wasn't so monumentally bored. Since leaving his dangerous job with the MI5 to concentrate on the family, even his new post at of Coordinator of Defense Studies at Army Staff COllege, Cumberley, has failed to keep his restless mind occupied.

All that changes when Patrick is suddenly taken into police custody and charged with the murder, several years previously, of a senior officer in the Anti-Terrorist Branch. Known only as Commander X, the dead man's body was found on the shores of a Scottish loch and new evidence point's to Patrick's involvement. Ingrid is left with no choice but to investigate in an effort to clear his name. No stranger to the case and the world of the secret services, this assignment is to proveher most difficult yet. With a General Election looming, she discovers that the arrest is part of a political plot to to discredit members of the Opposition party and it seems no one is willing to give her any help.

As Patrick's condition in jail worsens, Ingrid is determined to find some answers, but with Special Branch hot on herh eels, and the trail almost cold there seems no way forward. To add to her confusion, disturbing facts come to light that may mean Patrick was involved after all. As the horrific memories of their experiences together on the case are resurrected, Ingrid realizes that the only way to solve the mystery is to revisit the disused mining complex in Wales where the nightmare began, a decision that will have explosive consequences . . .