Riuscirà il nostro eroe a ritrovare il più grande diamante del mondo?

The film follows Jimmy Logan, a detective on a mission to retrieve a diamond taken from the British crown. His investigation leads him through various locales, including Montecarlo, Beirut, and Hamburg, ultimately discovering the thieves' hideout in a mental hospital.

With a runtime of 95 minutes, this film encapsulates the crime and action genres of the early 1970s. It showcases a narrative filled with tension and intrigue, as the protagonist navigates dangerous situations and deceptive characters.

The cast includes Ray Danton, Agnès Spaak, and Luciana Gilli, among others, who bring this thrilling story to life. The film's unique premise involving a gang of thieves and a mental hospital adds an interesting twist to the traditional heist narrative.