An employee of the Moscow Criminal Investigation Department was assigned a special mission: to infiltrate a criminal gang and find its leader, nicknamed Brilliant, who controlled all the crime on the streets of Odessa, where at that time an honest person was nowhere to be found.
A girl named Maria took on the alias Murka and the guise of a hardened thief in order to begin her covert work exposing criminal groups. She played the part so well that she quickly earned authority among the local gangsters. But not for a minute does she forget that her fiancé Ivan is waiting for her in distant Moscow, and she wants to return to him as soon as possible. Murka thinks this assignment will be the last of her career, but unexpectedly, everything goes off plan…
