Screen adaptation of two works by science fiction writers: “Noise Level” by Raymond Jones and “Shadow of the Past” by Ivan Efremov.

Two village boys - brothers Semyon and Pavel - serve a Moscow merchant-shopkeeper. They face harsh exploitation and hard forced labor. The brothers' life paths diverge. Unable to withstand the merchant's bullying, Pavel goes to the factory, becomes a worker, and later a professional revolutionary. Semyon remains in service. In the post-revolutionary period, Semyon, having been to the front and returning to the village, joined the kulaks, brutally dealt with representatives of the Soviet government, becoming the head of a gang of “badgers” hiding in the forests. A Red Army detachment led by Pavel is sent to fight the bandits...

A mysterious castle has stood on the island for 300 years, about which there are many legends and rumors. In reality, the castle is home to a boarding school, but local residents are sure that the ghost of the Green Hunter lives there. The boys also think they hear footsteps at night. And they were not mistaken - their search for adventure leads them to the sinister secrets of people who collaborated with the Nazis during the war.