The novella introduces readers to the head of the First Brigade of the Petrograd Criminal Investigation, Usoltsev, and his friend, the art expert Belov. In the events described by the author, not only they take part, but also exhibits from the museum of antique objects created by Usoltsev within the criminal investigation, the search for which was handled by the police. The reader will learn about the adventures of old clocks, Pushkin’s ring, Marat’s medallion, and much more.