Private detective Tatyana Ivanova was invited to the weekend by the husband and brother-in-law of her best friend Natalya Shadova. The wonderful idea of swimming naked in a lake at night almost cost Ivanova her life. The mysterious killer handcuffed her hands and stubbornly pulled her to the bottom. Tatiana miraculously managed to escape. Were they really hunting for her? Or maybe Natalya was really disturbing someone? A pleasant vacation became the beginning of a terrible and unsightly story, in which not only the Shadovs, who became clients of the famous detective, were involved, but also Tatyana herself, who almost died at the hands of a hired killer...