The life of Marina, a provincial girl who came to St. Petersburg to seek luck, at first develops quite standardly: college, work in a hospital, renting a corner - until a once famous actor falls in love with her, whose mistress she becomes. This event dramatically changes her fate. The criminal structures with which she finds herself involved after the murder of her loved one are trying to turn the girl into a killer, using her masterly use of weapons. And only a series of happy coincidences helps Marina, as it turns out - the illegitimate daughter of a powerful banker, to get out of the gangster networks that almost destroyed her and find her happiness.