Militiamen leave on an emergency call - robbery of the post office. When trying to detain, the robber explodes right in front of the guards. Loginov and Petrovskaya arrive at the scene. They are sure that the deceased Eduard Dorokhov had an accomplice who watched everything from the sidelines and had to turn off the timer upon successful completion of the operation. But finding out who could have forced Edward to do this dangerous business is not so easy.

Valery Zaborin's body was found in the courtyard of an abandoned house. It turns out that on the eve of his wife Anna turned to the police with a statement about the disappearance of her husband. Shortly before the incident, the couple quarreled, and Anna moved to live with relatives. Valery was last seen leaving the bar. The investigation reveals curious facts from the biography of the newly-made widow, but can they serve as evidence of her involvement in the death of her husband?

Liza Roslyakova was taken to hospital with severe chemical poisoning. The doctors were powerless, and a day later she died. The examination showed that the girl was poisoned with a chlorine-containing poison. Loginov and Petrovskaya, starting an investigation, learn about a mysterious man with whom Lisa had frivolous correspondence on the Internet. They learned from relatives that the mysterious addressee not only addicted Lisa to cocaine, but also supplied her with drugs by mail.