Giovanni Rocca is a cunning Carabinieri marshal who works at a barracks in Viterbo. A widower for many years, he has three children: Giacomo, Daniela, and Roberto. His investigations often involve his family, but thanks to his intuition, the marshal always sniffs out the right leads, managing to protect his loved ones and bring criminals to justice. The episode that will profoundly impact the first season is the untimely death of Carabiniere Antonio Fait, one of Rocca's best men, killed by a gang of drug traffickers. However, love is not lacking: the marshal begins a relationship with the pharmacist Margherita, dividing his time between her, his family, and his work.

This season, too, the Marshal must balance family and work, and it's not easy when Margherita, just days before her wedding, is arrested for the murder of her ex-husband, or when their honeymoon is interrupted by a murder. Furthermore, the Marshal must confront a serial killer who preys on young girls: the first is a single mother, the second is the sister of Corporal Banti. Fortunately, the Marshal intervenes just in time to prevent the killer from killing his daughter, Daniela. Rocca then has to give in to Margherita's desire for motherhood, and the two win custody of Tommy, the newborn son of the killer's first victim. Another happy event in the Rocca household occurs when Giacomo's girlfriend discovers she is pregnant.

This season, the Marshal is dealing with Giacomo, who is unsure about his choice of marriage, and with Tommy's biological father, who extorts money from Margherita in exchange for the child. Margherita is also jealous of Rocca's closeness to Dr. Ascari, the new deputy prosecutor, and to appease her, the Marshal promises her the honeymoon they never had. On the morning of their departure, however, a boss enemy of Rocca plants a bomb in his car, which Margherita has just gotten into, and the car blows up before the Marshal's eyes. The boss is later captured by Rocca.

Three years have passed since Margherita's death, but the wounds are still raw for the marshal, who nevertheless arranges Daniela's wedding. At Tommy's school, he then meets his teacher, Francesca, the daughter of his marshal from when he was young. She has always had a soft spot for him, and this is a good opportunity to start flirting with him again. Roberto opens a pub thanks to a loan from his father, Giacomo argues with his wife's parents after discovering his wealthy father-in-law's illegal sale of butchered meat, and Daniela lives with Marco, torn between love and petty arguments. Finally, Rocca finally declares his love for Francesca, who is about to marry someone else, but gives up everything for the marshal.

This season, the Marshal begins a beautiful friendship (which will develop into something more) with Dr. Solimeni, a medical examiner. Francesca is extremely jealous, and out of spite, she also makes herself very available to a new Marshal. Daniela gives birth to little Alice, Giacomo finally decides what to do with his life, choosing to become a Carabiniere like his father, and Roberto enters the seminary. After ending his relationship with Solimeni, the Marshal breaks his leg in a domestic accident and moves in with Francesca, who has also become single again. Eventually, Rocca and Francesca marry, but not before another domestic accident, in which this time she breaks her leg.

At the end of the five seasons of the television series, a miniseries entitled Marshal Rocca and his Childhood Friend was produced.