she must beware of the grey dwarfs and wild harpies that live there. One day she meets Birk, the son of a rival robber leader who has claimed the other side of Hell's Gap, and upon whom Ronia's father instantly declares war. Ronia and Birk develop a friendship that is as indestructible as the mountain fortress itself. But with their families sworn enemies they are forced to keep their friendship a secret until one fateful day when Ronia's father catches Birk... prompting Ronia and Birk to escape into the woods and fend for themselves. How long can Ronia and Birk survive in the magical forest? And will their fathers ever put aside their differences to get their beloved children back? Danish title: "Ronja Røverdatter".