The action-packed military-historical novel by the famous Russian writer Nikolai Cherkashin begins on the eve of World War II. The main character, illegal military intelligence officer Nikolai Lun, goes through many trials, but remains faithful to his cause and his Fatherland. The unexpected turns of his fate reveal the courageous character of the patriotic intelligence officer. The author gives his interpretation of the initial period of the Great Patriotic War, paints pictures of the heroic defense of the Brest Fortress.