Somewhere in the northern region of Italy, the loving Romeo family is introduced as Santo (Alessandro Gassmann) and his beloved wife Ingrid are seen visiting a school-level ice hockey match in which their daughter Sofia (Ginevra Francesconi) is participating. While the mother is mostly unable to understand why Sofia would be as aggressive as she is on the rink, the daughter seems to be more like her father, who encourages her to play hard and fair. Sofia also has a boyfriend named Hakim (Isnaba Na Montche), and Santo is fine with this, too, as long as the boy does not ever hurt his daughter. After the match, as a result of their win, Sofia is taken out by Santo for an off-road adventure in their car, as the girl has wanted to learn to drive on such terrain for a long time. During this day out, Sofia dearly wishes to take a picture of herself with her father to put up on social media, but Santo strictly tells her not to take any pictures of him. It has always been like this with Santo; he does not like or allow any of his family members to take any pictures of him. But Sofia is, of course, a teenager living in the Instagram world, and so she sneakily takes a photo of her father and puts it up on the internet. This photo seems to start a chain reaction somewhere in Milan as a group of menacing-looking men take a close look at the photograph.The very next day, Santo stays back for a while at his wood-sawing factory to look after the machinery and instead sends his brother-in-law Patrick (Luca Zamperoni) to pick Sofia up from practice. Patrick does so and takes the girl home, where he also spends some warm time with his sister Ingrid. However, this scene is quickly turned upside down when two armed men break into the house and kill Patrick and Ingrid. The attackers also take close pictures of Patrick's face and then realize that there is a third person in the house as well-young Sofia. While they spend some time looking for the girl, Sofia manages to stay hidden until the evening, when Santo also returns home. Stumbling upon the gruesome scene at his house, though, Santo spends no time mourning or trying to help his dead wife and instead takes his daughter away from the place. It seems the man has realized that the ghosts from his past are back for revenge.As Santo and Sofia get away from their house to a string of safe houses in an effort to evade their attackers, the man initially stays silent about what is going on and just keeps instructing his daughter around. But Sofia, after all, is her father's daughter, and soon she manages to throw a fit of rage enough for Santo to open up to her. It is now that Santo reveals that his name is not really Santo Romeo but Domenico Franze, and he was once part of the dangerous Sicilian mafia called the "Ndrangheta." It was actually his family, the Franzes, who were part of the mafia syndicate. As part of his familial duties, which were in terms of the mafia rules, Santo, or Domenico, had stirred up trouble with their rival mafia family, the Lo Biancos. Santo had killed the eldest son of mafia don Angelo Lo Bianco (Remo Girone). Ever since then, Angelo Lo Bianco has been looking for Domenico Franze in order to exact revenge for the murder of his son. But by that time, Santo had already seemingly fallen in love with a woman named Ingrid and had wanted to settle down and start a new life with her. He did not care much for all the violence and bloodshed and just wanted a way to get away from it all. It was due to this that he had fled from Milan and settled down in a remote town on the northern fringes of the country; he had also given up his given name of Domenico Franze and had instead taken on the identity of Santo Romeo. After the couple had their only child, Sofia, Santo was all the more determined to keep his wife and daughter safe from any harm and was resolute to never be found by the mafia again. This was precisely why he always kept insisting that nobody took pictures of him, for Santo is a man aware of the easy data breaches of the digital world.Don Angelo had gotten himself a new right-hand man, a tech expert by the name of Rudi Crisara (Francesco Villano). Before opening his own company, Crisara had worked with the government, and his expertise seems to be facial recognition technology. He had searched the internet with an old image of Domenico Franze and been led to the recent Instagram post by Sofia. The Lo Biancos sent their men to murder him and his family. However, the goons mistakenly killed the brother-in-law, Patrick, thinking that he was Santo, but Don Angelo could easily understand that they had missed their actual target. Since that first attack, the mafia keeps sending more men to track down and kill Santo and Sofia. While the two manage to escape each time, Sofia's boyfriend, Hakim, is killed by the criminals.As news of the double murder breaks out on television, the police identify the missing Santo as the notorious mafia henchman Domenico Franze, whom they, too, had been looking for all these years. With the police, as well as the mafia goons, all chasing him and his daughter, Santo decides to go to Milan to seek revenge himself. Santo was stabbed in one of the attacks and loses consciousness. Sofia drives him to Milan and gets medical help from an warehouse that is a front for illegal abortions. Santo is operated on and bandaged. Dan Angelo's men track down Santo to the warehouse and attack. But Santo manages to evade them and shoots them down. Since there is nobody else, he can entrust Sofia with, he decides to take the girl along with him as well and gradually give her training too. It just seems like Santo had been living a different life for all these years, but the brutal murder of his loved ones had sent him back to his old vicious self. In the knife-yielding training that he gives to Sofia, he ensures that the girl learns to use the knife, not in a way to kill her victim too quickly but instead in a way that would make her victim remember her face before dying.Moving on from such horrible parenting, Santo makes a marvelous plan for seeking revenge-while his whole situation was due to the fact that he had murdered the elder Lo Bianco son, he now plans to kidnap the younger son and hold him hostage. This younger son, Michele (Alessio Praticò), had also been introduced earlier, and the man is more invested in his duties as a businessman than those of a member of the mafia family. He is seen to have disagreements with his father as well but is not strong enough to overrule the Don's decisions. Michele says that this vendetta against Santo will cause harm to the family's business interests.Meanwhile, Don Angelo employs Rudi Crisara to now track down Santo and Sofia from the public traffic and security cameras in the city of Milan. Despite such measures, though, the ex-mafia henchman makes his way to the city and, together with the help of his daughter, kidnaps Michele Lo Bianco from his office. He then leaves a message for Don Angelo-the mafia boss is to confess to the police about all his crimes over the last thirty years and also to provide proper evidence about all his accomplices and network of funds, or else Santo will kill his younger son as well, just like he had killed his elder child. Santo believes that Don Angelo might negotiate with him in order to save his son, but the mafia boss is more determined to save his reputation and business than to protect his often-disagreeable son. He sends more men to Santo and Sofia's location, and Santo has to fight them off alone to protect themselves from murder.Meanwhile, Sofia and Michele have been alone in the safe-house where Santo had kept Lo Bianco hostage, and Michele now tries to convince the girl that both of them are in a similar situation. Just like Sofia had been forced into this life of hiding and evading all of a sudden, Michele says, he too has been forced to be a part of his family's blood-thirsty violence. He also tells the girl that her father had killed his elder brother, and Sofia seems to question her father's actions, at least for a brief second. Just then, she receives a call from Santo, who explains that he has gone on a mission with no return. Realizing that Don Angelo Lo Bianco would not stop at anything, Santo goes over to his lavish house, which also seems to be the mafia headquarters, and wipes out all the security all by himself. He then enters Angelo's room and strangles him to death. But Santo was very aware that such an action would very quickly draw the police onto him. Knowing that his and his daughter's lives were too damaged anyway, Santo makes it seem like he is about to pull out a gun, and the police immediately shoot him dead. The authorities then also find out about the safe-house and rescue Michele and Sofia from there, with the latter being put up at a Catholic orphanage.As time goes by, Michele Lo Bianco visits the orphanage and meets with Sofia. He promises her that he wants to stop the unnecessary blood feud between the families of Lo Bianco and Franze and asks her to meet him once she leaves the orphanage. A few years seem to pass, and Sofia leaves the orphanage as soon as she turns eighteen. Still holding memories of her father very dear to her heart, she goes over to Michele's office to meet him. It becomes clear that Michele actually wanted to kill her, for he now wanted revenge for the death of his father and had sent Crisara to look for her at the orphanage. But Sofia herself is driven by the same intention, for she identifies herself as a Franze, as the member of the family that her father had fought for and given his life for as well. She now stabs Michele to his death and ensures that he remembers who killed him as he suffocates in his own blood for thirty seconds. With her revenge mission now complete, Sofia walks out into the city and blends in with the crowd, just like her father had tried to do. She will perhaps never again put up any pictures of herself on Instagram after all this.