Dasha Vasileva and Colonel Degtyarev are invited to the anniversary of their good friend Fyodor Mukhin. The guests celebrated in grand style: they ate, drank, enjoyed themselves, and savored a concert featuring stars from the world of pop music. Mukhin is a wealthy man, and he’s absolutely not stingy—he spends money easily. And he’s a good person, too: he treats Elena, his wife Svetlana’s sister, wonderfully. He loves Nina, his sister-in-law’s daughter from her first unsuccessful marriage, and denies neither her nor his daughter Katya anything.
A happy family—rich, successful. During the celebration, Svetlana suddenly feels ill. So badly that she’s rushed to the hospital. There, it becomes clear: the woman was poisoned! And it’s clearly someone “one of their own.” Fyodor категорically refuses to involve the police; instead, he asks Degtyarev—who now runs a detective agency—to find the culprit. So how can he manage without Dasha Vasileva? And of course, Dasha will track down the criminal—even if, to do it, she has to turn into… an electrician!