In the Swiss Alps, Carla (Alida Valli) is preparing to scale the White Tower, a mountain her father died trying to climb. Although local guides warn her against doing so, an undaunted Carla assembles a crew of climbers who, much like her, accept the challenge for their own very personal reasons -- including a French author (Claude Rains), a British naturalist (Cedric Hardwicke), a former Nazi (Lloyd Bridges) and Martin, an American pilot (Glenn Ford) who is romantically pursuing Carla.