While Inspector Lorenzo Fabbri, Rex and Morini are attending a conference on Malta, Italian arts expert Ranieri falls victim to a poison attack. Gori demands that his investigators help their Maltese colleagues.

Katia has won a cruise for two and she is accompanied by Inspector Lorenzo Fabbri, who leaves Rex in Morini's care. But Rex manages to sneak aboard, and Fabbri hides him in his cabin. Meanwhile Katia discovers that Anna, who is presumed to have been physically abused by a passenger, has disappeared.

A few nights before the comet named after him is due to appear, astronomer Varinelli is working in the observatory when he is blinded by some eye drops he uses. An investigation discovers foul play and Inspector Fabbri and Rex get on the case.

When Countess Clotilde Sanfelice falls to her death from a window of her house in front of two horrified witnesses, a homeless woman who is seen fleeing the house is suspected of having murdered her. Rex and Inspectors Fabbri and Morini investigate the suspicious death.

Inspector Fabbri and Rex are called to investigate the death of rich kid Tony, who has been stabbed at his birthday party while his friends were watching a fireworks display.

Inspector Fabbri and Morini and Rex team up with the secret service to join in the hunt for a terrorist who has threatened to blow up a local conference.

The murder of night club singer Daria demands special commitment from Inspector Fabbri, as she was a close friend of Fabbri's on-off girlfriend Katia Martelli, a forensic expert and part-time singer.

While investigating a murder, Rex and his partner Inspector Fabbri uncover an illegal dog fighting operation involving stray dogs.

Inspector Lorenzo Fabbri attends a concert by pianist Flavio Bonomi, who has agreed to receive him afterwards. But when his cousin Antonio accompanies Fabbri to Flavio's dressing room, they hear a scream and find the pianist slain in his dressing room, where an MP3-player is playing.

At a female neighbour's party, Inspector Lorenzo Fabbri meets young student Ivana who comes to see him in the police department the following day. The law student from former Yugoslavia asks him to reopen the case of her mother Miliça who lost her life 17 years before. She does not believe in the suicide theory of the investigators at the time.

After a bad fall during an illegal motorcycle race, Stefano Bianchi dies on the way to the hospital. Since forensics confirm that his bike had been tampered with, Inspector Fabbri and Rex are called in to investigate his murder.

Professor De Vitis, a retired physician and president of a prestigious golf clubs in Rome, is found dead on his own golf course. The investigations are more complicated than expected for Inspector Fabbri and Rex, as almost all members of the club have a motive for the murder.