Most of all, Ivan Pavlovich Podushkin likes to spend time with a good book. But according to the law of meanness, every time a private detective settles down more comfortably with a volume of his favorite author in his hands, the doorbell rings, and another client appears in the office. Today, the visitor was Yuri Mironov, who is sure: he saw his mother in the shopping center. What's strange about this? Women love to shop. But Ekaterina Semyonovna died a few months ago. And soon Yura's mother-in-law and father-in-law went to the next world. And they left in a dream - a heart attack, a stroke. But after all, they didn’t get sick with anything like that ... Yuri suspects that their death could be beneficial to Andrei, a friend of Dusya, his wife’s sister. He is a sorcerer, a swindler, divorces people for money, and could well covet the inheritance. Mironov asks Podushkin to bring the villain to clean water. And answer the question: what did his late mother do in the store?