Terminally ill surgeon Kirill finds a job in a clinic where doctors struggle with supernatural phenomena. The only way to survive is to show his best side and convince the new management that the hospital needs him. Kirill plunges into the intricacies of the relationships of people, witches and demons, increasingly doubting that he is able to correctly determine who exactly represents good and who is evil here. The diagnosis is imperfect, and the enemy may be someone who initially did not seem to them. To avoid such mistakes, Kirill and his colleagues will have to spend a lot of time studying the circumstances of patients' illnesses.