Marine Ivanov, nicknamed Ballet, wins a landslide victory in military hand-to-hand combat competitions and receives an offer to move to a unit of naval reconnaissance saboteurs. Ivanov agrees. He brilliantly passes all the entrance tests, but "cuts off" on an underwater dive into a narrow pipe. The fighter is diagnosed with claustrophobia and is going to be transferred to another unit. But Ivanov would not have been Ivanov if he had surrendered so easily...