Test planes are disappearing and are investigated by an eccentric secret service man, who is helped by his reporter sister and a chauvinistic pilot.
English police raid an office and find Major Charles Hammond (Ralph Richardson), who lets himself be taken in. Hammond says that experimental bombers are disappearing. Barrett (George Merritt) complains his factory was searched. Tony McVane (Laurence Olivier) says he is the only unmarried pilot. Hammond is given a note warning of a secret agent. Confidential clerk Jenkins (George Curzon) asks waitress Kay (Valerie Hobson) for a kiss and gets slapped. A crew chosen by lot takes off. The plane flies at 330 miles per hour but loses power and ditches near a ship, which lifts it aboard. Tony goes with five planes searching and is the last one back, making charges of enemy agents. Hammond tells Barrett he removed the super-charger and signed his name. Kay questions Tony and reports to a newspaper; he criticizes her for that. The gang learns they did not get the supercharger and blames Jenkins for being wrong.
A car just misses Jenkins, and Hammond asks who is after him and why. They go to Jenkins' flat, but he is shot at the window from a passing car. Hammond makes the first of several calls to Daphne (Sandra Storme) postponing their date. Tony arrives to see Jenkins, and Hammond shows him the body. Tony picks up a gun and calls the police; but Hammond explains that Jenkins was a spy. At home with Tony, Hammond blames his sister Kay for reporting to papers. She defends herself and walks out. Hammond calls her the new woman and finds a compact. He goes to see Sonia but discovers she knows nothing about Jenkins. The Baron tells his gang not to kill Hammond, but he has a plan. Barrett and Hammond learn that the wreckage washed ashore. Barrett orders a test. Hammond's boss orders him to Palestine. As they quarrel, Barrett asks Tony to fly the plane. Hammond cooks and tells Tony he is off the case. Kay says she was dismissed too, but she doubts the plane was washed up. Tony suggests that Kay get married and stop working. Hammond finds that someone tampered with the plane and removed the engine. He questions men at a pub. Hammond calls Kay to investigate the Viking salvage vessel. Kay learns where it is going, and Hammond tells her to stop the test flight there.
Kay tells the guard at the gate she is Tony's fiancé. Barrett won't let him see her, but Tony sends her a washer and checks his gun. Tony takes off as Kay gets upset. The ship causes the engines to fail, and Tony puts it down near the ship, which brings the plane aboard. Tony pulls his gun but is knocked out. Tony leads the crews to break out, and they fight the crew as Tony takes over a machine gun. Hammond boards a destroyer; but before it blasts them, Tony takes over the ship and signals. In the final scenes Tony and Kay go off to wed, and Hammond learns that Daphne is married.
Droll British humor livens this spy story that reflects
concerns about an imminent war in which aircraft will be important.
Kay represents the modern working woman, but can Tony (Olivier)
adjust his arrogant attitude?