Our friends Martin and little crow Karak continue their magical journey. They must save the boy's family from the icy captivity of the treacherous old woman Izerga. How to do it? Who will help them? To find the answers, you need to go underground through the kingdom of shadows. Climb the dome of the sky and sail around the distant southern seas. Make friends with the powerful Werewolf Whale, help the Sky Hunter, save the stone turtle. And Izerga has already begun an invasion of inhabited lands, and only Martin can find an ancient weapon that can dispel the evil spell. Time is running out. Will our friends have time for the battle of the worlds?