On 10 May 1941 Rudolph Hess, then the Deputy Fuhrer, parachuted over Renfrewshire in Scotland on a mission to meet with the Duke of Hamilton, ostensibly to broker a peace deal with the British government. After being held in the Tower of London, he was transferred to Mytchett Place near Aldershot on 20 May, under the codename of ‘Z’. The house was fitted with microphones and sound recording equipment, guarded by a battalion of soldiers and codenamed Camp Z. Churchill's instructions were that Hess should be strictly isolated, and that every effort should be taken to get any information out of him that might be useful. During the ensuing thirteen months a psychological battle was waged between intelligence officers using the new Freudian techniques of ‘dynamic psychologies’, and the man who had been a heartbeat away from Hitler. Stephen McGinty uses new documentation, contemporaneous reports, diaries, letters and memos to piece together a riveting account of the claustrophobia, paranoia and high-stakes gamesmanship being played out in an English country house. CAMP Z is a ‘locked room mystery’ where the ‘locked room’ is a man’s head, and information which could help change the course of the Second World War lies inside a mind which no one can decide, with any degree of confidence, is either sane or insane. Hess was given a life sentence at the Nuremberg Trials, and from 1966 to his death in 1987 he was the sole remaining prisoner of Spandau Prison.