In 1956, Arkady Adamov’s story “The Motley Case” was published - the first Soviet detective story, thanks to which this genre was revived in the USSR. The film of the same name was one of the first Soviet detective films. When writing more than 30 works about MUR employees, the writer did not limit himself to conversations with criminal investigation officers. He sat in ambushes with them for hours, went out for arrests and searches, and attended meetings. The main characters of his works are Fyodor Tsvetkov and his student Vitaly Losev. For the first time, the story “The Motley Case” and the trilogy “Inspector Losev” are in one volume. The book is equipped with a detailed biography of the author and an illustrated history of the Moscow Criminal Investigation Department.