The First World War is underway. Secret documents were stolen from the General Staff building. A group of brilliant counterintelligence agents has been sent to search for them, tasked with finding and returning the papers at any cost. There are suspicions that the theft was committed by Japanese ninjas, so Vasily Shchepkin, who works under the guise of a film businessman, is brought into the case. Having many years of training in Japan and a black belt in judo, he knows Japan and the intricacies of life of the islanders very well... The prototype of the main character was the legendary man, the founder of sambo wrestling Vasily Sergeevich Oshchepkov. The plot of the book formed the basis of the acclaimed television series “Courier of Special Importance.”