A detective story about an impulsive, sometimes cruel, but experienced investigator Maxim Kholod, whose daughter disappeared under mysterious circumstances four years ago. Having failed to solve the case, Kholod despairs, he drowns his grief in a drink every day, and only his work saves him from a fatal step. Everything changes when a principled, fair, and dedicated linguistic forensic scientist Alexandra Kosovich joins the investigation, masterfully identifying criminals by their pronunciation, handwriting, and style of correspondence. With only one clue, his daughter's last note, Kosovich will try to unravel a case in which everyone is trying to hide their secrets.