| Director | Anthony Asquith |
|---|---|
| Budget | $615,000 |
| Box office | $1.2 million |
While travelling in London, Canadian World War II veteran pilot Jeffrey Buckenham sees baronet Sir Mark Sebastian Loddon on television leading a tour of his ancestral home in England. Buckenham recalls that he was held in a POW camp in Germany with Loddon, whom the Germans captured during the Dunkirk evacuation of 1940. Buckenham is convinced that Loddon is Frank Wellney, a British actor. Wellney and Loddon shared a POW hut in 1945 and bore a striking resemblance to each other.
Buckenham confronts Loddon and, with encouragement from Loddon's scheming cousin Gerald Loddon, writes to a tabloid newspaper, claiming that Wellney is posing as Loddon. In response, Loddon sues Buckenham and the newspaper for libel, although his memory is affected by his wartime trauma.
During the libel trial, Buckenham and Loddon tell their versions of wartime imprisonment and their escape. Buckenham had liked Loddon and despised Wellney. In spring 1945, the three prisoners escaped their POW camp and headed toward the Dutch border, seeking advancing Allied forces. Loddon wore his British army uniform and Wellney disguised himself in civilian clothes. One night, having gone without food for days, Buckenham left Loddon and Wellney alone to steal food from a farm. As Buckenham returned, he heard shots. In the mist, he witnessed one man in a British uniform lying on the ground, apparently dead, and another fleeing in civilian clothes. Buckenham believed that he had witnessed Wellney fleeing the scene of Loddon's murder.
During the trial, Lodden is found to be missing part of his right index finger, as had Wellney, and Loddon claims it to be the result of gunfire. Loddon also does not appear to have a childhood scar on his leg. Wellney's hair was prematurely grey, as is Loddon's. Buckenham recounts how Wellney often asked Loddon about his personal life during their imprisonment, and Loddon even joked that Wellney could be mistaken for him. As evidence mounts, even Loddon's loyal wife Margaret begins to doubt her husband's identity.
Defence barrister Hubert Foxley produces a courtroom surprise, revealing that the uniformed man that Buckenham had seen did not die. Although the man is alive, his face is horribly disfigured, his right arm has been amputated and he has become deranged. He has been living in a German asylum since the war, known simply as "Number Fifteen," his bed number. When Foxley brings the man into the courtroom, the man and Loddon recognise each other and Loddon's memory starts to return.
In desperation, Loddon's barrister calls Margaret to the stand, but she testifies that she now believes her husband to be Wellney, the impostor, implying that "Number Fifteen" is the real Loddon. Later, Margaret confronts her husband, who desperately walks the night trying to remember more. Seeing his reflection in a canal unlocks his memories. Wellney did try to kill him while his back was turned, but Loddon saw Wellney's reflection in the water and won their ensuing fight. He remembers beating Wellney harshly with a farm tool before switching their clothes and fleeing.
In court, Loddon remembers a medallion hidden in his jacket lining that Margaret had given him in 1939 before he left for France. By proving that the medallion had been in Wellney's possession all the time, Loddon wins the libel case and Margaret realizes that her husband is whom she had thought that he was. Buckenham and Loddon also reconcile, although Buckenham and the newspaper must pay damages.