Nikolay, a young aristocrat, joins the detective police against societal norms. Mentored by veteran Shchukin, they investigate a string of enigmatic crimes spanning the city's slums and elite circles.

A young man from the noble noble family of the Bezsonovs - Nikolay - by chance and at the behest of his heart becomes an ordinary official of the detective police. Colleagues accept him coldly, and only an experienced official, Pyotr Romanovich Shchukin, sees the future star of the detective in the young man. Together they are trying to uncover a chain of mysterious and dangerous crimes committed either in the city slums or in the boudoir of a socialite.