Robert Newton has been a railroad night signalman, stuck in a box for eight hours a night for twenty years. His wife died three years ago, and he's trying to raise their daughter, Margaret Barton. One night he sees two men get into a fight in the yards, and one of them goes down. Both disappear, but he recovers the suitcase they were fighting over. There are five thousand pounds in small bills in it. He takes it home, determined to take it to the police, but on his way, there are too many temptations: a five-pound smoking pipe.... well, easy enough to stick with his old one, but there are other temptations.
Can decency survive in a Film Noir world? Oh, easy enough for someone like Bogart, I suppose, who's sampled the world and found it wanting, or Robert Mitchum, who can barely open his eyes to see, let alone want. But what is a little man like Robert Newton to do? He seems to be unaware there is anything outside his poor, little world, until he finds his daughter scrubbing floors in a butcher shop, the butcher's wife shouting at her, and he realizes that with this money, she doesn't have to do that. She can have that new dress, they can go to the fair and see Simone Simon, the Atomic Mermaid, and maybe he can have her too....
There's something sleazy and slipshod about the best of British film noir that makes it much more compelling; there's an air of desperation about it, of little men slipping through the cracks that the relative richness of American noir never noticed, outside of a few like Gordon Wiles' THE GANGSTER. With supporting players like William Hartnell and Marcel Dalio, this one has it.