Book III

Hobbits Merry and Pippin escape from the Orcs who captured them when the orcs themselves are attacked by the Riders of Rohan. Merry and Pippin head into nearby Fangorn Forest where they encounter treelike giants called Ents. These guardians of the forest generally keep to themselves, but are moved to oppose the menace posed to the trees by the wizard Saruman, who has been chopping down trees in the forest to fuel fires for his furnaces.

Aragorn, Gimli the Dwarf and Legolas the Elf, tracking Merry and Pippin, come across the Riders of Rohan who tell them that they attacked the orcs the previous night and left no survivors. However, Strider is able to find small prints and they follow these into Fangorn, where they meet a white wizard who they at first believe to be Saruman, but who turns out to be their wizard friend Gandalf, whom they believed had perished in the mines of Moria. He tells them of his fall into the abyss, his battle to the death with the Balrog and his reawakening. The four ride to Edoras and persuade King Théoden that his people are in danger. In the process, Saruman’s agent in Edoras, Grima Wormtongue, is expelled from the city. Aragorn, Gimli and Legolas then travel to the defensive fortification Helm’s Deep while Gandalf goes north in search of Eomer’s men in Rohan to bring as reinforcements. At Helm’s Deep, they resist an onslaught of Orcs and Men sent by Saruman, and Gandalf arrives the next morning with the Riders of Rohan just in time. The fleeing orcs run into a forest of Huorn half-tree, half-ent creatures and none escape. Aragorn, Gimli, Legolas, Gandalf and the Rohirric army then head to Saruman’s stronghold in Isengard.

There, they reunite with Merry and Pippin and find the city overrun by Ents, who have flooded it with the nearby river, and the central tower of Orthanc besieged, with Saruman in it. After giving Saruman a chance to repent, Gandalf casts him out of the order of wizards. Wormtongue throws something from a window at Gandalf and those with him. This turns out to be one of the palantíri. Pippin, unable to resist the urge, looks into it and has an encounter with Sauron. Gandalf and Pippin then head for Minas Tirith in preparation for the upcoming war.

Book IV

Frodo and Sam discover Gollum stalking them as they try to reach Mount Doom to destroy the One Ring. Gollum hopes to reclaim the Ring. Sam loathes and distrusts him, but Frodo pities him. Gollum promises to lead them to a secret entrance to Mordor and for a time appears to be a true ally. They first stop at the Black gate of Mordor, where Gollum persuades them not to go in, where they would have been surely caught. They head south into Ithilien, and are captured by Faramir, the brother of Boromir. Faramir learns from Frodo of his brother’s death and of the plan to destroy the ring, and allows them to go on their way. Gollum leads them into the lair of Shelob, an enormous spiderlike creature, who inflicts her poisonous bite on Frodo. Sam resolves to finish the quest himself and takes the Ring. But when Orcs take Frodo’s body, he follows them and learns that Frodo is not dead but unconscious and now their prisoner. The last line of the book is “Frodo was alive but taken by the enemy.”