Sixth part of Jerry Cotton movies. Agent Jerry Cotton infiltrates a big crime syndicate that is planning a major diamond heist.

Pepe Nietnagel and his fellow students of the Mommsen school come up with all kinds of ideas to get out of doing any actual school work. This includes simulating suicides, setting off the air-raid sirens and abusing the school director's new broadcasting system. They succeed in sending their teacher to a sanatorium and get a replacement that turns out to not be so bad after all.

Isabelle, an editor of a lifestyle magazine who grew up without parents, finds out from the police that her father died not decades ago, but only yesterday. When she visits his farm, she discovers that she is also a big sister. Faced with the imminent institutionalization of her two young children, she has to make a decision: Career or family. A sympathetic caretaker makes it easier for her.

Norbert Lang inherits a hotel and has to deal with a multitude of problems at the end of the year. There's the pushy singer who wants to get closer to him than he'd like. The staff quickly takes off after arguments. When the heating starts acting up, he has to hire a repairman. But the repairman shows up with unexpected backup and causes even more chaos.

A famous conductor named Frederick falls with his plane in the house of a woman who spends a few days with her daughter. He was feeling increasingly disappointed with his fiancee, love of fame, and there is a crush at the time.

Although Baron Arvid von Frühling travels to the fashionable spa town with his fiancée Stephanie, he soon neglects her because of the Baden-Baden Grand Prix, which he is determined to win with his racehorse Eintagsfliege. The writer Victor Duplessis, known in the town as Casanova, seizes his chance and approaches Stephanie. When Arvid finds out about this, he challenges Victor to a duel, which turns out to be a strange affair: In the end, the two become friends. Arvid, who then dumps Stephanie, gets Victor to give him tips on how to seduce her, and soon they are both involved with the beautiful Margot. When the charming Charlotte arrives at the race, the love chaos is perfect.

Two wannabe burglars crack open a safe after overcoming numerous obstacles.