The Hyacinth Patrol
Published in the collection - novelization of episode 31 of the radio program of the same name as the collection.
In a bar in Cristobal along the Panama Canal, Harry Lime becomes involved in a rivalry between two men, Dolan and Nugent. Dolan is in love with Nugent's girl. He talks Lime into helping prove Nugent is a traitor to America so Dolan can have a chance with the girl.