In this chapter, Aragorn, Legolas, and Gimli are on the trail of Merry and Pippin following their capture by Saruman's Uruk-hai. The trio's pursuit leads them through the wilderness, where they are acutely aware of the growing darkness in Middle-earth, a direct consequence of Saruman's treachery and Sauron's influence. As they travel, they engage in discussions about the state of the world and the increasing threat posed by Saruman, whose forces are rapidly gathering strength.

Their journey takes them to the plains of Rohan, a realm known for its horse lords, the Rohirrim. The landscape is vast and open, contrasting sharply with the dense forests they have traversed. Here, they witness the signs of Saruman’s destruction, as the land bears the scars of his corrupting influence. The chapter paints a vivid picture of the natural beauty of Rohan, emphasizing the Rohirrim's close connection to their land and their horses.

As they traverse the plains, the three companions encounter a group of Riders of Rohan, led by Éomer, the nephew of King Théoden. The Riders, initially suspicious of the strangers, are soon convinced of their noble intentions. Éomer and his men are on patrol, searching for the Uruk-hai who have been raiding their lands. During their interaction, the group learns of the dire situation in Rohan, including the influence of Saruman over King Théoden, who has fallen under a dark spell, rendering him weak and incapable of protecting his people.

Éomer reveals that he has been following the movements of the Uruk-hai and has engaged them in battle, which showcases the bravery and skills of the Riders. They discuss the fate of Merry and Pippin, who they believe may still be alive, as the Uruk-hai have been seen moving south. The bond of camaraderie and mutual respect grows between the Rohirrim and the three companions, as they share their common goal of fighting against the darkness enveloping their world.

The chapter concludes with Éomer pledging to aid Aragorn, Legolas, and Gimli in their quest to rescue Merry and Pippin. This alliance signifies a crucial turning point, as the characters begin to unite against the common enemy. The Riders of Rohan represent hope and resilience in the face of overwhelming evil, and their willingness to stand by the side of Aragorn and his companions foreshadows significant events to come in the struggle against Saruman and Sauron.

Overall, 'The Riders of Rohan' deepens the narrative by introducing pivotal characters and expanding the scope of the conflict in Middle-earth, highlighting themes of friendship, loyalty, and the fight against tyranny.