While on board a liner bound for South Africa, Captain Stephen Dennett, a British army flier, meets Felice Falcon, a glamorous jewel thief. Felice, with her confederate Michael Barclay, is plotting to make a getaway with a haul of diamonds that have been cached at a mine by another accomplice and decides to use Stephen as her stooge. She charms Stephen into promising her entry into the forbidden precincts of the diamond mines, but is outwitted by him when he gets away with the jewels himself and turns them over to his friend, police commissioner Colonel J. W. Lansfield. Using the diamonds as bait, the two set a trap for Barclay, whom the police have been chasing for a long time. Their plans go awry, and Felice is caught in the trap instead and is sentenced to prison. When a murderous jewel ring then begins operation, the colonel offers Felice parole in return for her cooperation in trapping the gang, and she agrees to pretend that she and Stephen are a newly married couple who are delivering the jewels to the gang. As they await contact by the ring, Felice falls in love with Stephen and renounces her wicked past. When the gang finally contacts the couple, their cover is blown as the ringleader turns out to be Felice’s old accomplice, Barclay. However, the colonel comes to Stephen and Felice’s rescue and wins both their freedom as well as Felice’s permanent release from prison. More on Wikipedia or Mubi
Watch Adventure in Diamonds aka Diamonds are Dangerous (1940)
