Credit shark Herbert Baumann has been murdered. Suspicion falls on the go-kart driver Martin. The young man had borrowed money from Baumann. Martin, who asserts his innocence before Inspector Brandtner, is in mortal danger shortly afterwards.

Horst Bacher shot his wife in a quarrel. After that, he decides to kill himself and his children as well. He goes in search of Kathie and Klaus, who are wandering through Vienna on the run from him. Rex must find the two of them before it's too late.

The baby of opera singer Nina Martin is kidnapped from a hotel room. The kidnappers shoot the nanny. They demand a large ransom sum from Mrs. Martin. The first handover of money fails. The kidnappers are becoming increasingly nervous.

The Viennese homicide squad is looking for a dangerous telephone terrorist. With obscene calls and demands, he has caused the deaths of two women. With the help of the recorded voice, Brandtner has a perpetrator profile developed. Rex's help is indispensable.

In the middle of training, hockey player Pokorny collapses dead. The autopsy reveals that the athlete was murdered in a sophisticated way. Inspector Brandtner wonders whether the crime was really aimed at Pokorny.

Paul Tomek kills his twin brother Hans in an argument. Paul assumes the identity of the dead man. Shortly thereafter, Inspector Brandtner and Rex are called to a charred corpse. They still can't tell who the man is.

When a woman falls from a Viennese skyscraper, Inspector Brandtner and forensic pathologist Dr. Graf make a strange find in the mouths of the dead: there is a tarot card with a picture of a tower. Their investigations lead the officers from the homicide squad into the esoteric milieu. It doesn't take long for a tarot card depicting three swords to be found on another corpse. Leo Graf finds Robert Dietz with a triple stab wound that killed him instantly. What was Dietz's connection to the first victim? The trail leads to the card reader Natascha Kaminski, whose fingerprints can be found on the tarot cards. However, she steadfastly denies any guilt and puts herself in great danger, because she is also on the killers' hit list. Can Alex Brandtner prevent another murder, and will Rex succeed in arresting the perpetrator on his own?

The full moon killer already has two young women on his conscience. He always kills at full moon, cuts off the hair of his victims and puts it in cemeteries. But this time, the Viennese police under the direction of Alex Brandtner want to mess up his tour. When the moon is full again, the commissioner has all Viennese cemeteries monitored. The trick seems to have succeeded, because no corpse appears in any cemetery that night. But in the morning, art student Judith Geiger is found strangled at a tomb in the Vienna Woods. Crime scene tourism is booming, and Alex Brandtner breaks a sweat despite the dirty weather as he sets out to solve the third murder case. Rex and his colleagues don't have much time to solve the puzzle, because the next full moon night is sure to come.

Shock for Kunz: The dead man, to whom the police were called, is his former colleague Helmut Walz from the robbery department. Brandtner learns from Commissioner Sabine Kogler that Walz was suspended a few months ago for excessive alcohol consumption. Walz's drunkenness began after he arrested the notorious bank robber Hanusch, known as "the mole", but was shot to the cripple in the process. Hanusch later managed to escape, he fled to Brazil, but Walz did not give up the search for him even when Hanusch was declared dead. Thanks to Rex, Brandtner now secures a bullet case at the site of Walz's murder, on which is a fresh fingerprint of Hanusch. Rex and Brandtner follow the trail of the "mole" - deep down into the catacombs of Vienna...

Months after his violent death, the already heavily mummified body of the young professional surfer Peter Bachmann is found by sewer workers. In the search for clues, Inspector Brandtner finds what he is looking for in the victim's computer: Bachmann was apparently very busy chatting and offered himself as a playmate to couples in a sex chat room. Of course, his contacts have remained anonymous and have used online names. In order to expose them anyway, Kunz, Böck and Brandtner offer themselves as sex objects on the Internet. The reactions are varied, but before the investigators can record a success, another chatter is found murdered in his car. He was in contact with the same couple – codenamed "TwoForYou" – as Bachmann. Brandtner arranges a meeting with the couple...

A sensational exhibition opens its doors at the Vienna National Library. The work of Count Egon Reichenberg, an important botanist of the 19th century, was long considered lost and has now finally resurfaced. Legend has it that Reichenberg found the recipe for prolonging his life in Tibet. The count lived to be over 150 years old and finally died a violent death in the First World War. The prospect of great profit leads to the march of many shady characters who rummage through the count's estate for the coded recipe. The merciless race soon claims the first victims: Baron Felix Nordegg, a descendant of the Count, and the archivist Lutz are mysteriously killed. When Brandtner and Rex track down the mysterious recipe, the dog's life is also in danger...

A battered man's corpse lies in the paddock of a breeding bull. Dr. Graf notes that the stranger died of a broken neck and was apparently deposited with the cop to cover up the murder. The dead man is identified as the stable boy Josef Swoboda. At the same time, Brandtner receives the news that the expensive jumping horse Sirius has been kidnapped from Hermine Latzki's riding stable. What is the role of the shady trainer Arthur Stein, who seems too eager to link Svoboda to the disappearance of the horse? When Rex Stein catches him training a horse using cruelty to animals, Brandtner begins to suspect that Sirius has fallen victim to an accident and that Stein could be the mastermind behind a sophisticated insurance fraud...