They book it to Edoras for over a day, until suddenly they stop in their tracks.
Gandalf points to the heart of the high mountains in front of them, and asks Legolas to tell what he sees.
Legolas sees a green hill in the east, surrounded by a thorny fence; at the top is "a great hall of Men [...] thatched in gold" (3.6.7).
This is Edoras which has a large golden hall. That's the Meduseld.
They go to see Théoden King!
On the approach to Edoras, they ride through large mounds covered with a flower called simbelmynë—Evermind. This flower grows over graves and blooms year round.
The graveyard is for Théoden's ancestors. It has been in use for the past five hundred years.
As they pass, Aragorn speaks the poem of Eorl the Young, Théoden's first ancestor: "Where now the horse and the rider? Where is the horn that was blowing? [...] The days have gone down in the West behind the hills into shadow" (3.6.15).
As they reach the gates of Edoras, a bunch of dudes in chain mail stop them. Speaking the language of Rohan, they have a rather unfriendly chat with the travelers.
Aragorn is totally amazed that they're being so inhospitable. They're not even using the Common Tongue, for Pete's sake, even though that's "the custom in the West" (3.6.18).
These are Théoden's rules.
According to his new rules, no one is welcome in Rohan except the Rohirrim and men from Mundburg, in Gondor.
When they see that the travelers are riding horses from Rohan, they suspect that the guests are wizards, or spies from Saruman.
The guard looks troubled, and says he hasn't heard a word of this.
Gandalf commands the guard to open the gates and annouce Gandalf, Aragorn, Legolas, and Gimli to Théoden.
At the door of Meduseld, Háma the Doorwarden demands that they give up their weapons.
As Gandalf is an old man, so Háma allows him to keep his staff.
They walk into Meduseld and find an old man hunched in his throne. It's easy to see that at one point, this guy was tall and proud. But now he's barely a shell of his former self.
The man on the throne is King Théoden.
Gandalf tells the king that he has come back because a storm is upon Rohan.
Théoden calls Gandalf a "herald of woe" (3.6.55) and renames him Gandalf Stormcrow.
A pale man on the steps near Théoden agrees. He asks why they should welcome Gandalf with this news, when Théoden's son Théodred has just been killed less than five days before by orcs?
This man, Gríma Wormtongue, accuses Gandalf of doing nothing but stealing Shadowfax. Gandalf has brought no men, no weapons — nothing substantial in terms of aid. So how exactly is he supposed to help?
Baffled by their rudeness, Gandalf isn't afraid to make his disappointment known.
When Wormtongue manages to get in a nasty word about Galadriel, too, Gandalf basically tells Gríma to shut up about things he doesn't understand. Word.
Then, Gandalf raises his staff and the hall becomes dark.
Wormtongue whispers, "Did I not counsel you, lord, to forbid his staff? That fool, Háma, has betrayed us!" (3.6.65).
There is a flash like lightning, and Wormtongue sprawls on his face.
Gandalf warns Théoden that he has been listening too long to forked-tongued advice.
Théoden slowly stands, and a woman rushes to his side to help him. It's his niece, Éowyn.
Gandalf tells Théoden to breathe in the fresh air. (remember that he is not as old as he thinks).
So Théoden casts aside his old cane and draws himself up. Looks like Rohan's king again.
After admitting that his dreams have been dark lately, Théoden wants to know what should be done next.
Luckily, Gandalf is here to help. He tells the king that step number one is to get Éomer out of jail, where Wormtongue put him.
As they wait for Éomer to be brought to them, Gandalf tells Théoden all about what the Company has been doing (except about the Ring. He thinks it's better to leave that part out).
Théoden laments for the fall of Boromir: "the young perish and the old linger, withering" (3.6.88).
Gandalf tells Theoden that his hands would remember their strength if they graspt a sword hilt.
Eomer offers Theoden his sword.
When Théoden accepts the sword from kneeling Éomer, he lifts it, slashes through the air, and shouts: "Arise now, arise, Riders of Théoden!/ Dire deeds awake, dark is it eastward,/ Let horse be bridled, horn be sounded!/ Forth Eorlingas!" (3.6.97).
His guards immediately draw their swords and lay them at his feet. Éomer is filled with joy to see Théoden back to his old self.
Théoden commands Háma to bring his old sword and Wormtongue to him, while Gandalf advises Théoden to put his trust in Éomer.
It's time to prepare for battle against Sauron. Dun dun dun.
Théoden declares his willingness to go to war with the Men of the Mark, and then gives instructions for the people of Rohan to seek refuge in the mountains, in the Hold of Dunharrow.
Meanwhile, Háma returns, kneels, and hands Théoden his old sword, Herugrim. Wormtongue had it locked up with a lot of other things he'd stolen. The sniveling little guy takes this opportunity to grovel for forgiveness.
Théoden informs Wormtongue that he can redeem himself for his bad advice if he rides forth with the Mark. Yeah, like that'll happen.
Wormtongue days. He suggests that he remain behind to govern the people of Rohan seeking refuge in the Hold of Dunharrow.
Gandalf asks, "How long is it since Saruman bought you?" (3.6.122). He also accuses Wormtongue of lusting after Éowyn.
Éomer does not like this. He's angry, too, because he wants his sister Eowyn to be safe.
Théoden's verdict (with Gandalf's advice) is this: either Wormtongue will ride with the Mark against Saruman, or else they will give him a horse and let him go wherever he wants.
But if they meet again, Théoden "will not be merciful" (3.6.128).
Wormtongue suddenly runs away down the stairs, the coward.
Théoden sends his guards after Wormtongue, while Gandalf explains that Wormtongue has been feeding Saruman information all along.
It turns out he was the one who convinced Théoden not to send Éomer after marauding orcs.
Luckily, Éomer disobeyed, or Merry and Pippin would be in a pickle, that's for sure.
Now that that business is over with, a grateful Théoden gives Gandalf Shadowfax permanently. Now there's a gift.
The king's men give Aragorn, Legolas, and Gimli a bunch of armor for the coming war, and Éowyn brings a cup for them to drink from before they go.
As he drinks from the cup, Aragorn is troubled by something he sees in Éowyn's eyes.
Before Théoden rides out, he names his nephew Éomer his heir, just in case he dies in battle. And when he asks who will remain behind to guard the non-fighting people of Rohan, Háma tells Théoden that the people trust in the House of Eorl.
Éomer's decides whether to go and fight or to stay.
Éowyn, his sister is left in charge.
Gandalf whistles and Shadowfax, who had been running wild in the fields, runs up to greet him. He leaps on the horse's back.
Aragorn shouts, "Behold the White Rider!" (3.6.174).
The host of Rohan rides out behind their king and the White Rider, as Éowyn stands on the palace steps watching them go.