During the period of illegal activity, the Bolsheviks had to fight numerous opponents, including the secret political police of the autocracy. The book offered to the reader convincingly shows how difficult and complex this struggle was. The first and second editions of the book, published in 1918 in the Zadruga publishing house, for a long time were inaccessible to a wide circle of readers. Addressed to everyone interested in the history of the CPSU.