A young American bomber pilot Gene Summers (Massie) is sent to Nazi-occupied Paris to kill a man believed to be betraying his colleagues in the French Resistance. He had received rigorous training by his handler Maj. MacMahon (Albert). He seems enthusiastic and ready to do his job.
Upn arriving in France, Summers begins to realise that there is a difference between killing a lot of people and one person up close. He says, "When I dropped bombs I wasn't there at the other end." His doubts grow when he finds that his victim Marcel Lafitte (French) is a gentle henpecked husband, who dotes on his cat "Mimieux," he begins to feel that the man may not be guilty.
The killing scene is particularly dramatic, with Lafitte screaming "why" and the cat staring up at Summers.
Summers is racked by guilt afterwards, but returns to London to carry out other duties.
The famous stage actress Lilian Gish is the pilot's mother, The film was based on an original story by Downes. He was an important OSS officer involved in numerous operations during the war, according to histories of the era. He became a writer after the war.
The movie won three BAFTA film awards.