The film tells about the surgeon M. D. Knyazev, who works at the All-Union Scientific Center of Surgery: M. D. Knyazev is in his office, preparing for an operation, performing a heart operation. View of the hall of the barocenter in the clinic. Carrying out an operation on vessels in a pressure chamber. Doctors at the patient's bedside. Surgical nurses preparing for the next operation. Operation of the Symphony apparatus during heart surgery. MD Knyazev talks about his work (synchronously).