About the book: 1929 / A detective novel is a kind of intellectual game. Moreover, this is a sporting competition. And detective novels are created according to strictly defined laws - albeit unwritten, but nevertheless mandatory. Every respected and self-respecting detective writer strictly observes them. So, a kind of detective credo has been formulated, based partly on the practical experience of all the great masters of the detective genre, and partly on the promptings of the voice of conscience of an honest writer.