A new case for the cult detectives! Not by coincidence, a mysterious videotape falls into the hands of Jupiter Jones, Pete Crenshaw and Bob Andrews during Jupiter's birthday party in Rocky Beach. On it is a recording of Jupiter's long dead parents. In their message they want to communicate to their son the key to an especially tricky riddle.

Whenever a criminal is killed in London, a black Jaguar is nearby, with a white cat always sitting in the passenger seat. Inspector Higgins and Inspector Lane find a joker card on all the victims. Their investigation leads them to a diamond smuggling ring.

Lady Osborne's gardener becomes the victim of a burglar when he catches him in the Lady's house. Soon more mysterious murders occur and Inspectors Higgins and Lane suspect a connection between the victims and the Lady's long-dead husband.

An encounter with a blind man ends unexpectedly for Susan Howard. The supposedly helpless man stuns and kidnaps her. The case is handed over by the Home Secretary to Sir John, the head of Scotland Yard. He entrusts Chief Inspector Higgins and Superintendent Lane with the investigation. Their investigations quickly lead Higgins and Lane on the trail of murder, white slavery and blackmail.

16-year-old Sophie Reiner is living a happy life, but then her friend Karen is murdered after a visit to a disco. Sophie's perfect world is shattered. She falls in love with the charming detective Mike Kleist and begins a secret affair with him. When another of Sophie's classmates is murdered, the situation comes to a head. Finally, Sophie's father becomes the target of the investigation. But the murderer has already chosen his next victims: It's Sophie and her mother...

Computer scientist Dr. Mary Cameron is certain that love can be predicted with numbers and is not just fate. Her boss sees great success in this: the algorithm she has developed is to help singles find the right partner on the dating platform "Cupid's Match". Amanda and Zac are chosen as a promotional campaign, who, as a couple according to the algorithm

Petra Hoffmann is in her early 50s and pregnant. She is not carrying her own child though, but that of her daughter. Midwife Lena Lorenz has been looking after mother and daughter for a while and the pregnancy has been unproblematic thus far, but shortly before the birth the family starts to break apart.