Private detective Tatyana Ivanova could not even imagine that her new client would be an employee of the fitness club to which her friend Lena brought her. Sergei, a handsome and athletic guy, outlined the essence of the matter to Tatyana: someone was writing to him on the Internet, on a dating site, making threats. But he threatens not Sergei himself, but his friends. And Sergei only warns who he is going to attack. Sergei did not pay attention to this, and the very next day his friend was attacked and beaten. The attacker did not stop there: he wrote who would be the next victim of the attack, and only Sergei has a chance to save his comrade. It was then that he turned to Tatyana Ivanova...