A real downer starring Robert Newton, Simone Simon, Marcel Dalio, and Margaret Barton.
Newton plays a train signalman, Bert Mallison. One night he witnesses a fight between two men, one of whom is pushed into the water. Mallison goes out to try and save him, but only recovers the man's suitcase. It's loaded with money.
Mallison plans on calling the police, but when his boss yells at him, he changes his mind. He goes home and hides it. He doesn't touch the money, but since it's there, he dips into his savings to buy new clothes for his daughter (Barton) and take her to an amusement park.
At the amusement park, they attend the show The Vanishing Mermaid. She is Camelia (Simone Simon) in a bathing suit who is dunked in water and disappears. When Mallison observes her boss being abusive, he runs in to protect her. Later, he runs into her at the pub. She is very kind to Betty, his daughter, who gives her their address.
Unfortunately, Betty is overheard by Brown (Hartnell), the thief who killed the man and wants the suitcase. He is already suspicious of Mallison - after all, he had a birdseye view of the proceedings and seems to be throwing money around.
A French police officer, Dupre (Marcel Dalio) has come to England to recover the money, which is from a casino heist. So he is putting pressure on a desperate Brown.
The situation becomes complicated when Camelia becomes involved and finds out about the money.
This is a very good film, a real noir, the story of a lonely widower trying to be a single dad who sees two glittering baubles - money and a woman - and fights with his conscience so he can have both. Both mean trouble.
Robert Newton is excellent and sympathetic as Mallison, and Barton does a wonderful job as his daughter. The beautiful, seductive Simon is convincing as a cool, ruthless golddigger. All of the acting is very effective.
For a bit of trivia, Margaret Barton, despite looking like a young teen in this film was 21 at the time and often played younger roles due to her size. Born in 1926, she was married to actor Raymond James, for 47 years, until his death. In 2018, at the age of 92, she married again. She and her husband are believed to be Britain's oldest newlyweds.