The work of a textual critic is akin to the work of a detective. The book by the creative researcher Mikhail Bulgakov and the famous text critic Lydia Yanovskaya includes works written in different years, but, unfortunately, remained unknown to the general reader. Years of studying the writer's life and work, working on manuscripts, and friendship with Bulgakov's widow, Elena Sergeevna, led Yanovskaya to the creation of an amazing book filled with little-known facts and textual discoveries.