A vacationing journalist investigates the mysterious death of a composer and debunks the theory that it was suicide.

U.S. Embassy employee Lee Cochrane and his wife, Sue, receive a shock when they discover that their 18-month-old son, Simon, has disappeared in London. He was last seen with their nanny, and the couple seemingly have no leads that might help police Detective Craig in his investigation. The media sensationalizes the incident, causing an unnecessary distraction as the couple prepares to confront the culprit face-to-face.

In a Swiss Alpine resort shortly after the War an army officer and upper-class Humpy Miller both set their sights on Mary, the landlord's daughter. When the two come down with chicken pox they are put in the charge of fellow guest Miss Cartwright, who turns out to be Humpy's old nanny. The two Englishmen unite not only against her tyranny but against a dense Greek who is also after Mary.