Retired colonel Ermolaev dies as a result of a heart attack. However, his former colleague Captain Zvonarev does not believe the official version and suggests that the colonel was killed. He knows that many people have recently wished for Ermolaev to die: over many years of service in the police, he had collected an impressive archive of compromising evidence on the powers that be and, according to rumors, was going to sell it profitably. Zvonarev begins an investigation and soon becomes a participant in mysterious and dangerous events that finally convince him that Ermolaev did not die a natural death...