Anatoly Lunin is a former clinical psychologist, and now a consultant in the operational investigation group on high-profile crimes. A unique method based on the peculiarities of his psyche helps Lunin solve crimes. He can get used to the role of the criminal, literally get into his head, and restore his motives. Anatoly knows that his abilities are a mental illness that he has to hide. His boss, Colonel Pokrasov and journalist Drapova seek to expose the hero, but Lunin is saved by the intercession of the high authorities — General Mordvinov. Anatoly has a difficult relationship with his colleague, a full—time criminologist psychologist Arina Solodovnikova. However, with each new case, her opinion about him changes — Arina is convinced of Lunin's professionalism and unusual talent.
In the new season, Dr. Valery Lunin, a clinical psychiatrist and forensic psychologist working with the Major Crimes Investigation Unit, decides to leave the department. But by a twist of fate, he is forced to begin cooperating with the FSB alongside a new partner, Polukarov. His longtime adversary, journalist Daria Drapova, after suffering a psychotic breakdown, unexpectedly becomes Lunin’s patient—and her attitude toward him changes dramatically.
Meanwhile, Lunin’s ex‑wife Marina and their daughter Anna return to Moscow. The girl has inherited her father’s gift—and his burden: she can “see inside people’s minds” but also suffers from his dissociative disorder. Now Dr. Lunin must teach his daughter how to live with the illness, even as he struggles with his own demons.