Britain is mired in bloody stalemate on the Western Front and questions are being asked in government about the leadership of the army. Soldier spy Sandy Innes is summoned from his undercover work in Belgium by the new Secret Service to investigate. Officially transferred to Field Marshal Haig's headquarters in France to prepare agents for the next big push, his secret mission is to spy on Haig's intelligence chiefs. At GHQ, no one is interested in Innes's inside knowledge. Instead, he is attached to an advance assault group dubbed The Suicide Club. His fellow intelligence officers have little faith in the top secret information being fed to Haig by their superior, and as Innes digs deeper he begins to suspect treachery.