Celebrated amateur detective Albert Campion awakes in hospital, accused of attacking a police officer and suffering from acute amnesia. All he can remember is that he was on a mission of vital importance to His Majesty’s government before his accident. On the run from the police and unable to recognize even his faithful servant or his beloved fiancée, Campion struggles desperately to put the pieces together—while World War II rages and the very fate of England is at stake.