A bored U.S. housewife trades places in London with her jet-set twin, and one of them winds up dead.

Since the death of his colleague, which was partly his fault, Lieutenant Nick Gentry lives a lonesome life. Reporter Joan wants to write a story about him, and seems to be interested in other ways too, but he rejects. Instead he falls in love with his new neighbor Irene and witnesses how she's repeatedly beaten up by her husband Allan. One day, when Allan threatens her with a gun, he shoots him. Certainly self-defense -- until it turns out, that Alan's gun was made inoperable...