The first version of this thriller, produced in 1934 in England,was a critical and popular success which helped to establish Hitchcock's reputation. The storyline, based on a Bulldog Drummond book, was simple yet effective.

A British couple on vacation in Switzerland learn of an assassination plot against a foreign consul. Their daughter is kidnapped to guarantee their silence. Her rescue, and the prevention of the assassination, at the famous Albert Hall in London, called for a spectacular shoot-out which was inspired by the notorious Sydney Street Siege at the beginning of the century.

For years, Hithcock wanted to remake the film. When he revived the project in mid 1950's, he decided to retain the general storyline, but move away from the straight thriller aspect and focus on the family's predicament. In the new version, the family is on vacation in Morocco, when they become involved in web of international conspiracy to assassinated a prominent diplomat during a concert at Albert hall.

The holiday turn into a nightmare when their 10 year old son is kidnapped. The story has fewer twists and turns then most Hitchcock narratives.

The climax of the film centres around the crashing of orchestra cymbal's which will the sound of the assassins shot. Thus music takes on an added meaning as