A quartet of international crooks -- Peterson, O'Hara, Ross and Ravello -- is stranded in Italy while their steamer is being repaired. With them are the Dannreuthers. The six are headed for Africa, presumably to sell vacuum cleaners but actually to buy land supposedly loaded with uranium. They are joined by others who apparently have similar designs.
Jack Clayton, the Scotland Yard inspector played by Bernard Lee, is named after the film's cameraman, Jack Clayton, who later became a well-known director.
The only thing standing between you and a watery grave is your wits, and that's not my idea of adequate protection.
Revealing mistakes: When we see the newspaper article about Vanmeer's murder, early in the film, only the first paragraph belongs to the story; what we can see of the second and third paragraphs is about a need for new school buildings.