After the successful completion of Gordeeva's case, Zoya is offered to become an investigator. She has to combine her new job with raising her nephews, who now live with her. Meanwhile, the corpse of a young woman Svetlana Chichagova, who was poisoned with antifreeze, was found. However, according to indirect signs, Neupokoeva understands that Svetlana could not commit suicide. Zoya will have to convince her leadership - Colonel of Justice Kira Pugachev - to open a murder case.