At the time of the former USSR, a lot of literature about intelligence was published in the current post-Soviet expanses. Some of the books have deservedly become bestsellers. Unfortunately, "gross" authors write about intelligence by hearsay, amateurishly mixing its various types into one heap, and for piquancy generously seasoning their creations with a sauce of intelligence passions, which misleads readers.Vladimir Sokolov's book is profitable differs from the previously written one, as it is a popular science military-historical work. Despite the serious approach of the author to the work, the material is presented in an accessible, logical and consistent way and is designed for a wide readership. A detailed, reliable and knowledgeable description of the history of military human intelligence is given. Serious works have already been published on this topic, which in a short time have become a bibliographic rarity. This circumstance in no way diminishes the value of Vladimir Sokolov's book, since the reader's interest in this topic is far from being completely satisfied. In addition, the author found new, previously unused historical and literary sources, which saves him from repetition and gives the book additional interest.