The film is adapted from J· R· R. Tolkien's classic magnum opus, set 200 years before the trilogy, tells the fate of the Helm family, King Rohan "Hammerhand". When Woolf, lord of the Black Barbarians, launched a fierce offensive to avenge his father's death, Helm and his people were forced to retreat to the ancient fortress of Fort Clarion, which would later become known as the "Valley of Helms". In the midst of a desperate situation, Helm's daughter, Hera, rises to the occasion and begins to lead her people in a rebellion against a mortal enemy who intends to destroy them once and for all.