About the book: 1979 / Magazine version (“Ural Pathfinder”, No. 5 and 6 for 1979). Illustrations by N. Pavlov. Chernenok Mikhail Yakovlevich was born in 1931 in the village of Vysokaya Griva, Toguchinsky district, Novosibirsk region. Graduated from the navigation department of the Novosibirsk River Technical School. For a long time he worked in the shipping inspection of the Ob Basin and in the West Siberian River Shipping Company. In 1969 he switched to newspaper work, then was editor of the prose department at the Siberian Lights magazine. Member of the USSR Writers' Union. For many years, M. Chernenok was elected assessor of the people's court. Here he came up with the idea of ​​a series of stories “The investigation has established” (“The Secret of the Old Well”, “Entrusted to the Criminal Investigation Department”, “Kukhterinsky Diamonds”, “Bet on Losing”), where the main character was criminal investigation officer Anton Biryukov. The stories were published in the magazine “Siberian Lights” and published as separate books in the West Siberian Book Publishing House. They have been translated into Czech. “Under Mysterious Circumstances” is a new story that continues the cycle “The investigation has established.” M. Chernenok is published for the first time in the Ural Pathfinder.