Again with his white coat, Doc faces his first day as head physician. He has new responsibilities to manage without neglecting patients, despite pressure from the Administrative Director who threatens to close the department. Fortunately, Doc can count on his team, although Julia has not set aside the idea of leaving and Richard is challenged by the new residents.

The news of Doc's memory upsets the ward's balance: Agnese fears that recovering his memory will destabilize Andrea's new life, while Damiano is worried about the effect this might have on Giulia. Doc, on the other hand, is increasingly elated, although it is not easy to wedge the therapy prescribed for him by Enrico between the thousands of commitments as head physician.

Doc continues to dig into his memory and, now that he has finally met his "sail," he has a clear lead to follow. He has Giulia at his side who, in addition to Andrea's problems, must also think about her career. Meanwhile, a famous travel blogger is admitted to the ward and entrusted to Federico's care. But this encounter is likely to create more than a few problems.

The search for Doc's memory seems to have come to a dead end, but Andrea has found a new "sail": the upcoming choir competition in honor of Mattia. While he tries to convince Agnese to accompany him, in the ward Federico ends up under pressure, and Riccardo is faced with a case that sends him into crisis and pushes his relationship with Martina to the limit.

Doc sees some of the certainties he had about his past collapsing and, to shed light on what happened, he also drags Giulia into his search, who is challenged by the idea that her relationship with Andrea was based on a lie. Angelo, a patient whose condition forces Martina to prove herself, has problems with his past, too.

The therapy sessions with Enrico seem to have side effects on Doc, who sees his ability to take care of patients called into question. Agnese seizes the opportunity to crush his research into the past, while Giulia is convinced that Andrea should not give up, despite his problems: in fact, his brother Fabio is admitted to the ward.

Doc finally knows how to track down the woman he is looking for, but he must first find the courage to do so. Meanwhile, Ric faces the case of an undisciplined personal trainer, while Damiano must deal with the hospitalization of a model, his brother Samuele's girlfriend. This case threatens to bring up old family grudges.

The fear of discovering the secret about his past is too strong for Doc. However, this denial of the truth drives him away from the ward, much to the surprise of Giulia, who has to take care of a patient who, just like Andrea, seems to be hiding something. Meanwhile, Enrico must deal with Barbara's assaults, which may be hiding more than just infatuation.

Doc enters a competition with an AI: if he does not want to be replaced by a machine, he must find the correct diagnosis for a patient before the computer. Martina, on the other hand, is given a case that forces her to come to terms with her conscience, while Agnese is confronted with a terrible decision to protect one of Andrea's secrets.

Agnese's words have created a rift with Andrea, who must also come to terms with being away from Giulia, who is in Rome for research. Meanwhile, Teresa must work wonders to find a place for Diana's daughter, admitted despite her mother's doubts. Elisabetta is also admitted to the ward after a few days of illness, maybe an indication of a more serious problem.

A violent earthquake sows panic at the Ambrosiano Hospital. Lin is afraid for her family; Ric decides on Laura's proposal; Federico has to perform a surgery for which he does not feel ready; Martina has an encounter that threatens to bring up her secret; Giulia, on the other hand, has to manage the ward because Doc is stuck in an elevator and has to save a pregnant patient.

The deadline to submit the research is approaching, but Giulia seems to have other things on her mind. Even Doc struggles to manage the myriad commitments: there's the meeting with the funders and then there's Carolina, who is in town for a few days. Everything takes a back seat, however, when Lin's sister is hospitalized. A case that will force the resident to come to terms with her father.

Giulia must make a decision about her personal life that will also affect her career. While Martina faces the most difficult exam of her life, Ric takes on a case that will force him to come to terms with Alba's ghost. Lin and Federico, on the other hand, get back to work on the database, but they risk bringing Doc closer to the truth that Agnese has been hiding from him.

Andrea is forced to come to terms with Agnese's illness, but unexpected news from America reawaken his hopes. At the hospital, however, the new head physician is challenged by a case that will force someone to make a terrible compromise. Meanwhile, Lorenzo is entrusted with a patient who has arrived from a nursing home and has been prescribed an overdose of medication.

In the ward, the moment of truth has arrived. As Federico faces his last day at Ambrosiano Hospital and Martina makes a decision that leaves the rest of the team stunned, Doc must come to terms with the truth Agnese has told him. He is convinced that it can't get any worse - until the man responsible for it all, his worst enemy, is admitted.