The fourth episode of "Public Disorder" kicks off with a haunting flashback, where Nobili is summoned as a key witness. He delivers a compelling testimony against two police officers accused of assaulting a youthful detainee. Meanwhile, in the present timeline, Franco’s mother captures the nation's attention on television, her voice trembling as she pleads for justice, delving into the depths of guilt and parental responsibility. Nobili, Mazinga, and Marta are glued to the screen, the gravity of her words echoing in their thoughts.
Mazinga steps in to assist Anna with Pietro's pension matters, escorting her to his son’s workplace within the pension department. Giancarlo, though initially hesitant, eventually agrees to lend a helping hand. As they depart, a poignant revelation unfolds: Anna had contemplated divorce from Pietro. However, the allure of police life now binds her, filling her with resentment.
The Nobilis family eventually make their way to the police station, as Emma works up the courage to report the rapist. In her absence, Nobili sneaks a peek at the report, his heart sinking upon realizing the perpetrator is a mutual friend, one they both once admired. Tragedy strikes as he recalls that the boy once ignored Emma when they were both in love. He took possession of her by force.
Elsewhere, Marta, facing a night shift, decides to entrust Stefano to Agata's care for the night. Agata and Stefano bubble with excitement, while Marta maintains a polite demeanor. Later, she catches Salvatore in a state of agitation, anticipation palpable as Lena's visit nears. Their six-month romance has been marked by lavish gifts, a swanky hotel booking, and even a flight arranged by Salvatore. Marta's suspicions grow, prompting a fierce outbreak of emotion from Salvatore. Her turmoil deepens when she bumps into Nobili, who confides in her about Emma’s harrowing case. Worried sick, she watches as he creates a decoy online profile, hoping to befriend the perpetrator.
Embarking on their latest assignment, the units face the daunting task of quelling local opposition should a dumpsite be reopened on their territory that very night. Nobili and Mazinga approach the protestors with civility and empathy, understanding their plight. Meanwhile, Salvatore skips the mission to meet Lena, only to be stood up. Learning from a colleague that she never boarded her flight, his frustration mounts, prompting him to request a trace on Lena's phone number.
The following day, Mazinga accompanies Pietro to the station, witnessing the latter's constant agitation due to his disability. Pressured by the District Attorney to revisit Susa Valley and narrate his account, Pietro defiantly declines. As he exits, greeted cheerfully by his unit, Pietro redirects his seething anger towards Mazinga, lamenting that his life is shattered without their camaraderie.
Returning to their mission, the site's approval is confirmed, and Mazinga braces for an explosive confrontation. When his comrades chant "ACAB" (All Cops Are Bastards), he sternly silences them. Upon arriving at the site, Mazinga hesitates to advance, as protesters implore them to safeguard their land. Instead of joining the baton charge, Mazinga retreats to the van. Enraged, Nobili confronts him for abandoning his brothers-in-arms. Mazinga coolly responds that he is weary of his duties, while Marta looks at him with sorrowful eyes.
Back at the precinct, Marta attempts to check on Salvatore, who avoids her. Discovering Mazinga packing his belongings, Salvatore tries to halt him. The sergeant declares his refusal to follow in Pietro's footsteps, insisting that life holds more than just policing. Mazinga then seeks forgiveness from Giancarlo, but it's too late, as Giancarlo reproaches him for not apologizing to his wife sooner.
Agata finds herself uninterested in skating, prompting Stefano to advise her against going. Marta, with a troubled look etched on her face, remains silent. Emma, on the other hand, appears jittery and on tenterhooks. She admits her affection for her parents but struggles to express it at the moment. Daniela's tears flow freely, while Nobili is visibly disturbed.
Elsewhere, Mazinga reveals to Anna that he has resigned from his duties. She responds with a sense of relief, kissing him gently. The bodycam footage, now revealed, shows Mazinga using a lighter to incinerate the device upon entering the woods. Presently, it's discovered that he had been concealing it within a pot.
In the concluding scenes of Public Disorder Episode 4, Nobili finds himself cyberstalking the rapist. Mazinga visits him during this time, handing over the bodycam and urging him to fulfill his duties as a policeman. Nobili is taken aback, and Mazinga confesses that he has disappointed many and is weary of the cycle. He has taken a medical leave and plans to retire soon. With a simple nod, Nobili acknowledges this and departs.
