A 16-episode detective story about the impulsive, sometimes tough, but experienced investigator Maxim Kholod, whose daughter disappeared under mysterious circumstances four years ago. Having never solved the case, Kholod despairs, he drowns his grief in a glass every day, and only work saves him from a fatal step. Everything will change when the principled, fair and dedicated linguo-criminalist Alexandra Kosovich joins the investigation, masterfully identifying criminals by pronunciation, handwriting and correspondence style. With only one clue - the last note from his daughter, Kosovich will try to unravel a case in which everyone is trying to hide their secrets.