Both Scotland Yard and an amateur American sleuth are tracking a master criminal known as The Frog. This moniker refers to the bulging-eyed mask worn by the evildoer, and is reflected by the frog icons painfully tatooed onto the forearms of his henchmen. The trail leads to the country manor of an enigmatic, steely-eyed nabob, whose repressed son has eyes for the artistes at the Lolita cabaret, and whose lovely daughter captures the fancy of both the American playboy and the villain himself. Murder, kidnapping and seduction ensue.

Rival gangsters from Chicago move to London and attempt to extort money from rich Britons.

For business reasons, Rosemary is supposed to marry Peter, a stranger to her, according to her father's wishes. However, while fleeing from America back to Europe, Rosemary and Peter meet under assumed names and fall in love.

Musician Peter Karmann, whose main profession is teaching Asian languages, goes on a grand tour of Africa with a ballet troupe. Unfortunately, the well-behaved Peter looks very much like the notorious smuggling baron Jack Castillo. As soon as he arrives in Tangier, he soon ends up in captivity. Rescue comes in the form of the beautiful and clever Marcella, who is madly in love with Peter.

Thomas Mann's witty and intimate story of a irresistible scoundrel.

Double murderer Dr. Crippen is using every means possible to search for a manuscript that he suspects is in the possession of the daughter of the man who was executed in his place.