Several characters return to the little town where, years ago, the police commissary Cattani was set up and murdered by the Mafia.

A desperate chase is given by The Core and two countries magistrates to catch the new drug lords that are aiming at deluging drugs into Europe's Eastern countries from a former Nazi concentration camp in the West.

Cattani hides the truth about his daughters disappearance from his wife and colleagues while at the same time fighting opposition in his work place.

Saverio comes home to reunite with Nuzzio against the higher powers of the Mafia, but these are alert and after him, after torturing his mistress in St. Petersburg. Also after him, is his wife, still under the protection of Oleg, Saverio's bodyguard.

Cattani focuses his investigation on rich business men, while his private life is getting more and more difficult.

Cattani tries to settle the score with his enemies.

Cattani discovers what happened the night Marineo was murdered, but the information is dangerous.

Police Inspector Cattani fights a losing battle to save his loved daughter's sanity, after what she suffered (see "La Piovra", original mini-series). He loses her, and his only trusted magistrate in the fight against The Octopus.

Judge Silvia Conti and Davide Licata are in a quest for vengeance against the Mafia.

Corrado Cattani replaces the murdered Palermo chief of police Marineo.

The detective exposes and destroys the man who secretively had taken the place of the octopus's head - but the crime will not stop, because the criminal's son escapes with enough power to restart it all.

The local television channel, owned by Olga Camastra, puts the blame of her husband's death on Silvia Conti's harsh interrogation of the old man. Saverio's ascension to power seems unstoppable: he masters over Nuzzio with his superior intelligence, and helps him escape an ambush; the Barrotti gang is massacred by Nuzzio's men; and he breaks and enters into the countess's palace, frightening her, and demanding the names list.

Silvia is blamed for another strange death, the young commissary Breda is sent away to his hometown far north - something he had requested before he was into this case - and their only witness, Sara, is pressed by a police inspector and the new prosecutor to deny her earlier testimony.

Cattani sets a trap for some of the key mafia players, resulting in the kidnapping of his only daughter.

Cattani's major achievement so far leaves him without friends in Rome; his former teacher explains between whiskeys how easy it is for an intelligent man to fall into criminal ambition.

Sara and Biagio, her brother, create an extortion gang, named after the village's suburbs where they live. They are taking the "business" out of Nuzzio's hands.

Anna Antinari gets hold of documents that are essential for the arms deal, and trusts her life and that of her child daughter Greta to the good monks who were already hosting Cattani. For the mafia in liaison with a member of parliament, monastery walls are no protection against a new massacre.

Giulia reconciles with her grandfather Nicola, and her second meeting with chief inspector Corrado Cattani is yet a probe for his loyalty to duty. One man ends a life of power tragically; the other hangs desperately to life because, as Giulia says, "He lost; and quite a lot!"

Cattani uses a TV interview to reveal he found out about one of The Octopus telephone numbers. That is enough to spread havoc in the criminal rang, but the mafia leaves the American investigators no escape.

Cattani falls in love with Giulia, but his inquest does not go far, until Giulia's father dies, and her grandfather takes hold of the family bank again.