When bank robber Dakin Barrolles is on the run from the police, he manages to sneak into the house of respectable Sir John Lasher and his wife Sandra. He finds the drunken Sir Lasher in the course verbally abusing his wife, fearing his upcoming military service.
Barolles tells the banker off, then robs the couple of their car and a special locket with pictures of the couple inside. Unfortunately, Barrolles is caught as he is about to leave the house, by Inspector Henry James Cork of the Scotland Yard. Barrolles manages to escape once again from the inspector, and disappears into the night.
Some time later Cork finally manages to track the robber down, discovering that he enlisted under a false name and became a respected soldier in her Majesty's Army. Corks intelligence says that Barrolles was killed at Dunkerque, but he is in fact still alive. His face was terribly misfigured during battle and he was sent to a hospital in Scotland to recover.
Since the doctors have no identification of the man, they look at the locket, which Barrolles is still carrying, and believe he is the man on the picture. They reconstruct his face so that he looks just like the picture, which is the face of Sir John Lasher. When Barrolles wakes up he decides to play along and pose as Lasher. He figures he can use it to rob the man's bank.
Barrolles goes back to Sandra, pretending to be her husband returning from the war, with amnesia, explaining the fact that he doesn't remember a thing about their lives together. Sandra is happy with him returning as a different man than when he left her.
After some time Barrolles falls in love with Sandra, but is still set on robbing the bank. He goes to work as Lasher, and starts his first day with ordering a large transfer of gold. He meets a man named Hugh Burnside, who apparently is the uncle of Lasher's young mistress. Hugh asks Lasher/Barrolles to accompany him to the residence of a Lady Constance Fraser.
Hugh has discovered that Barrolles is a fraud, since he knows that Lasher is alive in a prison camp in Germany. It turns out Hugh and Lady Constance are the heads of a Nazi spy ring in England. Hugh threatens to hand Barrolles over to the police if he doesn't cooperate and transfer the gold to them. Barrolles sees no other alternative than to play along. Cork discovers the truth about Barrolles' operation and impersonation of Lasher. He comes to the Lasher home and returns the locket to Sandra. She realizes that Barrolles is an impostor. She goes to visit Barrolles at the bank office and unknowingly becomes part of the gold transfer.
Barrolles had time to send a message to Cork about the transfer, who arrives in time to stop the gold from being shipped. Cork catches the two spies and tells Barrolles that he is pardoned by the government because of his distinguished service for his country.
Barrolles returns to Sandra and they confess their love for each other, ut decide to put their relationship on hold until the real Lasher is safely back home from the war.Nancy Kelly ................ Lady Sandra Lasher
Edmund Gwenn ................ Inspector Cork
John Loder ................ Sir John Lasher
Henry Wilcoxon ................ Dakin Barrolles
Melville Cooper ................ Dr. Crownfield
Gilbert Emery ................ Sir Clive Heathcote
Norma Varden ................ Lady Heathcote
Leyland Hodgson ................ Henderson
Lionel Pape ................ Hugh Burnside
Lilian Bond ................ Lady Constance
Leo G. Carroll ................ Craven