Nastya Olkhovskaya's department gets a new case. The owner and his mistress were killed in a country house. The killer was clearly not interested in the man — he killed him on the doorstep, and spent several hours with the woman, even cooked for her, and then drowned him in the bathroom, throwing rose petals into the water. It soon becomes clear that this is just the beginning — the killer of couples is not going to stop. And now danger threatens all couples in love in the city! Anton Shcherbatov, a consultant and data analyst, is involved in the case.