Scotland Yard detectives attempt to solve a spate of safe robberies across England beginning with clues found at the latest burglary in London. The film is notable for using a police procedural style made popular by Ealing in their 1950 film The Blue Lamp. It is known in the US as The Third Key.

The crew of a deep-sea trawler face a series of life-threatening challenges on the open ocean. While the ship battles brutal weather and treacherous icy conditions (the metaphorical "black ice" of the sea), the plot centers on the internal and external conflicts of the sailors.

Travel agent Emrys Jones and tourist Patricia Dainton fall in love in sunny Italy. Jones has led Dainton to believe that he's fabulously wealthy, and she has likewise deceived him. When the truth inevitably outs, it hardly matters, since hero and heroine now love each other for themselves rather than their bank accounts.

A father and son go to Paris to help each other find love.