Awakening from a dream of Gandalf the Grey battling the Balrog, Frodo Baggins and his friend Samwise Gamgee find themselves lost in the Emyn Muil near Mordor and soon become aware that they are being stalked by Gollum, the former owner of the One Ring. After capturing him, a sympathetic Frodo decides to use Gollum as a guide to Mordor, despite Sam's objections.
Meanwhile, Aragorn, Legolas and Gimli pursue the Uruk-hai to save their companions Merry and Pippin. The Uruk-hai are ambushed by a group of Rohirrim, while the two Hobbits escape into Fangorn Forest and encounter Treebeard, an Ent. Aragorn's group later meets the Rohirrim and their leader Éomer, who reveals that they have been exiled by their king Théoden who is being manipulated by Saruman and his servant Gríma Wormtongue into turning a blind eye to Saruman's forces running rampant in Rohan. While searching for the Hobbits in Fangorn, Aragorn's group encounters Gandalf, who, after succumbing to his injuries while killing the Balrog in Moria, has been resurrected as Gandalf the White to help save Middle-earth.