The television series follows the work of a Chief Detective Maria Shvetsova (played by Anna Kovalchuk)[2] of a St.Petersburg Saint Petersburg District IC Investigative Committee of Russia.

District IC Investigative Committee of Russia headed by Nikolai Filonov (Senior Advisor of Justice) would long have turned into the organization for the collection of statistical crime related data, if not for Maria Shvetsova and her colleagues – experienced homicide detectives Vinokurov & Kurochkin.

Maria is not afraid to take the initiative and, in spite of irritation of Vinokourov, she always prefers to go to the scene herself in order to interview witnesses and gather evidence.

Thus, having begun the investigation of the murder of the owner of the collection of antique coins Florinskaya – she pretty quickly discovers that the prime suspect, whose "candidacy" is insistently being suggested to her by the relatives and friends of the deceased, has actually nothing to do with this crime.

Further on the Petersburg investigative committee will discover a strange crime – the murder of a former skipper Glebov poisoned by an unknown neuroprotective drug.

In her personal life, Maria has full support of her family – her loving husband Dmitry Luganskiy and daughter Zlata.

Under the leadership of Kovin Maria finally gets the required degree of freedom, that for so long was dreamed of at the times the superior chair was held by her longtime foe Filonov.

Assessing the benefits of the new situation, she is reconciled to the fact that her own merits as a leader again, have not been evaluated "at the top ", and with her head dipped in the cases, the flow of which does not dry out for a minute – she continues investigating: murder and other crimes caught in her field of vision, is almost everything that absorbs the attention of Shevtsova... until her husband Luganskiy has been sent abroad for a six months business trip... Shvetsova continues to work as a public defender at the Zanevsky SC, simultaneously helping her first husband Andrew with a divorce, during which she discovers signs of fraud by his new wife, and also tries to guide the girl Liza on the right path and maintain relationships with children.