Professor Sigmund Freud, the famous psychologist and father of psychoanalysis, receives an invitation from Pope Leo the Thirteenth to come to Rome and conduct an important study for a good reward. The professor needs money, and he has long dreamed of visiting Rome. And he sets off. The Pope wants the professor to psychoanalyze the three most influential cardinals, whom Leo considers his most likely successors. The elder feels that he is living his last days, and considers it his duty to prevent an unworthy person from being elected to the papal throne after his death. And the reasons for concern are quite real: just recently, the bodies of a dead young man and girl were found under one of the windows of the Vatican Palace. Double suicide is doubtful. But if there was a murder, is one of the hierarchs involved in this? An exciting and sometimes risky game begins, the rules of which change several times over time...