The detective agency "Partner" used all its forces to find the criminal. Within a few days - three strange murders. First a schoolgirl, then her older sister Olga, and a day later - their friend Lyuba. The motives are unknown. The investigation has reached a dead end. Lisa, a new employee of the agency, joins the investigation. She has a special gift at her disposal that none of her experienced colleagues possesses: female intuition. The cards are in her hands!..