It seemed that there was everything for a wonderful holiday: sun, sea, flirting. And suddenly this whole radiant picture is spoiled by terrible news: one after another, the bodies of three young women who died a violent death were caught from the sea... It seems that a maniac is operating in the boarding house “Southern Night”! Young police officer Vsevolod, under the guise of a vacationing banker's son, is trying to find out which of the company of his new acquaintances, carefree young guys, is brutally killing women, taking advantage of their irrepressible passion for romantic adventures. It would seem that everything points to one specific person, but... there is no evidence! The criminal, as it turns out, is extremely cunning and careful. And, besides, he does not act alone - unexpectedly he has a companion...