There is a serious emergency in the optics store - the seller was shot. An advertising stand with the logo of Vision Style, a company specializing in eye color changing, was found near the body. It all looks as if someone deliberately put her next to the corpse after the murder. From the vice president of the company, Georgy and Irina learn that he recently received a letter with threats and accusations of devilish change in people's appearance. Investigators realize they are dealing with a paranoid fearful of someone with an altered appearance.