The film is adapted from J.R.R. Tolkien's classic masterpiece. The story is set 200 years before the trilogy and tells the fate of the family of Helm the Hammerhand, King of Rohan. When Wulf, the Dunlending lord, avenged his father and launched a fierce offensive, Helm and his people were forced to retreat to the ancient Hornburg fortress, which was later called "Helm's Deep" (also translated as "Helm's Deep"). In desperation, Helm's daughter Hera rose up and began to lead the people to resist this deadly enemy who intended to completely destroy them.