A jeweller is killed in a gang robbery leaving the daughter as the only witness. When the police can't build a case against him she decides to go undercover to infiltrate the home of the killer's brother. Slowly she is drawn into the world of the rival gangs.

Scotland Yard investigate when a woman, apparently the estranged wife of a London painter, is murdered with a shotgun in rural Surrey at the same time as the artist's striking model with her long black hair disappears.

When heavy fog prevents any flights from leaving London Airport, a group of passengers are put on a bus driven by Percy Lamb to drive to another airport. The fog is that heavy Percy doesn't know where he is going or that he is carrying stolen gold bullion that the robbers and police are relentlessly pursuing.

When Germany invades Holland in 1940, a British intelligence officer and two Dutch diamond merchants go to Amsterdam to persuade the Dutch diamond merchants to evacuate their diamond supplies to England.