On a family vacation in Switzerland, Bob (Leslie Banks) and his wife, Jill (Edna Best), become friendly with a man staying in their hotel. When the stranger is assassinated in their presence, the vacation turns dangerous. Before dying, the stranger passes along a secret to Jill. Then, to keep the couple silent, a band of foreign assassins kidnaps their daughter. Offered no help by the police, Bob and Jill hunt for their daughter as they try to understand the information that they have.