Two rivals are out to recover a cache of stolen jewels. The thief who originally stole them has just gotten out of prison, however, and he is looking for his twin brother, who knows where the jewels are hidden. Complications ensue.

Reporters Peter Drante and Conny roam Hamburg’s Reeperbahn at night, uncovering three intertwined tales: Lilli, a aging dancer, searches for her missing husband who once shot her in a jealous rage; multimillionaire Alexander Borgess faces blackmail over past indiscretions; and Karin Thorwaldt seeks Borgess’s aid to secure her fiancé’s acceptance by her conservative father.

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.

A scientist creates an invisibility formula, but it is stolen by a master criminal who uses it to commit even bigger crimes.

On the way from Mexico City to Caracas, a plane crash-lands on an uninhabited island. The criminal Mario Bertelli terrorizes the other survivors. He prevents them from sending emergency signals.

Shortly before the First World War, the son of a Prague butcher is called up for military service in the Austro-Hungarian Army of Emperor Franz Joseph, proving to be a very incompetent recruit.

Seduction has to be learned: One orders a harem to his hotel to prove that only she is the one. The other slips into boy's clothes to stand her ground. Handsome hotelier James Sander is idolized by pretty girls and earns a lot of money on the side. But the girls are a thorn in the side of his tax consultant Hilde. She has fallen in love with the attractive bachelor and has worked out a perfect plan to win James' heart. Mike's band has also arrived at his hotel. Sweet Bibi slips there into the role of her sick brother, trying to keep the secret of her womanhood and stand her ground as a drummer. Her game of hide-and-seek is in vain - because Mike is not the only one who has his eye on her. The turbulence in the hotel reaches its climax when hotel servant Pankraz smells a crime in James Bond style and stages the total confusion.

After many years on the oceans, sailor Hannes Wedderkamp has finally returned to Hamburg. On St. Pauli, Hannes sings songs from the sea in the hippodrome of his best friend Pitter Breuer on the Reeperbahn with the "Quetschkommode" songs and cares for the audience.