London, 1940. With the country in disarray after the retreat from Dunkirk, desperate for any kind of advantage against an implacable and well-organised enemy, Winston Churchill sanctions the creation of a special unit separate from the military and intelligence services. The Yellow Room, named for the single chamber it occupies in the War Office, is so secret that only a handful of people know what it really does. Staffed by the old, the disabled and the damaged, armed only with their minds and arcane knowledge, the Yellow Room fights the Nazis on a strange front somewhere between espionage and the imagination, between magic and science. But the war drags on and principles are compromised in the quest for victory. And Anthony Crane, the Yellow Room's leader, refuses to compromise.