A novel by the grandmaster of Russian science fiction. Special services, the right heroes, secret military techniques, technical innovations and an invincible heroic spirit. The mysterious death of physicist Istomin triggers an avalanche of events in which people, spaces and times are involved. The investigation, which began as usual, changes dramatically due to the discovery of the device he designed. As Sledkom Major Nikifor Somov finds out, the customers for the research are defense industry workers, and the en-drive is a powerful weapon. However, even its creator did not imagine that the device could change the direction of the flow of time, replicate parallel universes and essentially cancel death. Now this is reality, and the heroes will have to unravel the loops of time, bypass the paradoxes of probability and look for the truth in the fog of relativity.