Russian detectives unwind the ball of the most intricate and cruel crimes. They are consummate professionals, the best cops in town. Even on the most dangerous missions, this quartet never loses their sense of humor. It is it that helps them find the most incredible ways out of any situation. They uphold the law and emerge victorious.

A poker player and expert in psychology investigates cases in an unorthodox way.

The series concerns the everyday lives of the operatives of the "murder" department of the Petrovsky District Department of Internal Affairs of St. Petersburg.

None of the operatives voluntarily wanted to go to work in the new district of Vaselkovo, cut off by the railway "ring". Four "shot down pilots" were found in the department: Yegor Ozhogin, who began to drink frequently after the death of his wife, Anatoly Davydov, whose hussar adventures did not please the authorities, Mikhail Belsky, who carried out a successful and profitable operation with financial assistance, and the naive orphanage boy Sergei Matyukhin, who regarded his appointment to the department as a promotion.