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.

It's the day of the primary simulation for Doc: Andrea for a day returns to wear the gown, but a sudden computer blackout of the hospital's systems forces him to a series of risky choices.

Agnese's condition rapidly deteriorates and Andrea receives the support of the whole ward in the attempt to discover what disease she is suffering from. However, the accusations levelled against him regarding his involvement in the falsification of data on pharmaceutical trials risk him having to leave the hospital for good.

A special episode set ten years earlier. Andrea, an enthusiastic doctor who is still together with his family, has an opportunity to make a career jump for the first time. But it is a struggle to hold everything together: suddenly finding himself involved in a rivalry with his colleague Marco, he risks losing sight of who he really is.

Locked in the ward in a forced quarantine, doctors are engaged in a fight against time to stop a multidrug-resistant bacterium that has infected them all.

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.

Professor Andrea Fanti, a brilliant Head of Internal Medicine, has his life turned upside down when the father of a patient who has died in his ward shoots him in the head. Andrea survives the shooting, but loses his memory of the last twelve years of his life. When he wakes up, he struggles to recognize his colleagues, his family and the man he had become.

Andrea is hospitalized in the Internal Medicine ward, in the hope that over time the place most familiar to him will help him recover his memory. Giulia oversees his rehabilitation, but finds herself dealing with a different man to the one she knew.

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.

Carolina, who is suffering from a mysterious illness, is admitted to the ward, triggering a series of conflicts between Andrea and Agnese that they will have to overcome for their daughter's sake. Meanwhile, a flashy influencer attracts the young trainees' attention and Alba cannot disguise her jealousy towards Riccardo.

A patient sheds light on a secret about Lorenzo's private life that causes a stir throughout the ward. Meanwhile, Gabriel and Elisa must attempt to reconstruct the life of an elderly inpatient who appears not to remember anything about himself, but repeatedly utters a single word.

After finding the medical file on the patient who died because of a mistake, Andrea tries to reconstruct what happened before the shooting that wiped out his memory. Marco, who was responsible for this death, and Agnese are uncooperative. Alba and Riccardo struggle to rebuild their relationship and things also get complicated between Gabriel and Elisa.

Andrea finds himself in hot water when a former trainee accuses him of falsifying data from a pharmaceutical trial: unable to defend himself due to his amnesia, he seeks confirmation from people close to him. In the meantime, Lorenzo has to fight to get Chiara on the transplant list and Agnese has a sudden illness.

Andrea returns to the ward as an assistant to the trainees, who were terrified of him just a few weeks earlier and find it hard to get used to the unexpected role reversal. While he tries to win back his ex-wife, his collaboration with Giulia on the case of a young manager proves to be challenging and full of surprises.

The arrival of a patient who is particularly important to Giulia intensifies the competition between the interns and Andrea has an opportunity to really get to know them. Meanwhile, he involves the ward in the search for his email account password, which could help him reconstruct a key part of his past, but which someone wants to hide from him at all costs.

A train accident turns the Internal Medicine ward into an improvised emergency room. All the doctors are required to do their best to deal with the emergency. One of the wounded is a girl who reopens an important chapter in Riccardo's past that the young man had considered closed forever.

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.

After a new memory, Andrea finds it hard to believe what his memory seems to be suggesting to him, and he asks Enrico to discontinue treatment. Even on the ward, the situation is far from quiet. In addition to Rita, a young girl who refuses chemotherapy, Andrea and his team have to deal with the case of a patient they know all too well.

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.

In an attempt to return to his role as a father and to help Carolina recover from her illness, Andrea starts to pursue Agnese again. A bad headache creates problems for Gabriel while treating a patient. Elisa and Riccardo have to deal with an aspiring astronaut.

Lorenzo has issues again with his ex-girlfriend Chiara, who is then hospitalized after overdosing. Marco and his wife feel increasingly threatened by the research that Andrea is carrying out on Satonal, the experimental drug that appears to have caused several deaths. Meanwhile, Gabriel has to explain to his community that he intends to settle in Italy.

All the secrets come to light in this special episode, a tribute to the medical heroes of the pandemic.

When he is one step away from regaining the primary, Doc is forced to a painful confession in front of the whole department.

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.