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.

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.

Giulia brings Andrea back to the ward for a patient who has asked to be exclusively examined by him and who does not know about his current condition. An error caused by his amnesia puts all the trainees under pressure. Meanwhile, Alba is forced to confront the resentment she feels towards her mother.

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.

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.

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.

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.

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.

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.