The story of how one committed "small" betrayal leads to a tragedy. For all in this life we need to pay, but also anger and thirst for revenge, gained for years, can be dangerous. This anger can come back to haunt you, as a hydraulic shock in physics. Three classmates went to the same technical institute, but for fifteen years had lost sight of each other. Years later, in coincidence Sergei Samsonov and the thief Avance, climb into someone else's apartment. This apartment belongs to a former friend - classmate Konstantin Chistov. Chistov once betrayed Sam. He wrote a denunciation on him, because of what Sergei was expelled from the institute a week before the diploma defense. Sam, who accidentally finds himself in Chistov’s apartment, plans his cruel revenge….