A sudden attack by Wulf, a clever and traitorous lord of Rohan seeking vengeance for the death of his father, forces Helm Hammerhand, the King of Rohan, and his people to make a daring last stand in the ancient stronghold of the Hornburg.

A young mermaid makes a deal with a sea witch to trade her beautiful voice for human legs so she can discover the world above water and impress a prince.