Professor Razumov was beaten to death near the institute where he taught history. The police ruled it a “no case”: it turns out that the culprits were random passersby. But try to find them! The victim’s closest circle inspires complete trust. His colleagues have to leave out any version suggesting their involvement in the murder. Razumov’s suspicious student, Vlad Neznámov, also couldn’t have committed the crime because of his physical frailty. And then private detective Tatyana Ivanova, at the request of the grieving widow, takes up the investigation and discovers certain facts that show the victim from a completely unexpected side…