An old soldier helps a young boy find his mother, who's been kidnapped to the magical underwater kingdom in a remote Russian lake.
A Baba Yaga's grand-daughter gets into the argument with the young son of Kashchey and decides to leave the magic forest.
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.
