Once they get down the mountain, the Company holds a council: either they have to go on or go back to Rivendell.
Frodo decides that they can't go back to Rivendell; that would be shameful.
Gandalf suggests one way forward – they could go through the Mines of Moria – but it's not a good way, and Aragorn is against it.
Boromir offers an alternative: they could go far to the south, through the Gap of Rohan and into Gondor.
Gandalf objects that this would bring them too close to Isengard and Saruman. Also, they can't afford to lose too much time.
Now that they have failed on Caradhras, they need to get out of sight for a while.
Moria is not Orc-heavy right now: most of the Orcs of the Misty Mountains were destroyed in the Battle of the Five Armies.
Gimli agrees to go through Moria. He wants to see the halls of Durin.
Aragorn has been through Moria once, but he doesn't want to repeat the experience. Still, he will follow Gandalf's lead.
Boromir says that he won't go through Moria unless the entire Company votes against him.
Legolas does not want to go either.
Frodo decides, "I do not wish to go [...] but neither do I wish to refuse the advice of Gandalf" (2.4.30).
He votes to wait until morning to decide.
Aragorn suddenly realizes that the howl of the wind is actually the howl of wolves. They have no choice now: they have to go to Moria.
They agree to set out for the door on Caradhras' south-west face the next morning.
They climb to the top of a hill as a defense for the night; there, they find a ring of stones.
Bill the pony trembles and sweats as he listens to the wolves growing closer.
There is a "great dark wolf-shape" that appears at a gap in the ring of stones.
Gandalf shouts, "Listen, Hound of Sauron! [...] Gandalf is here. Fly, if you value your foul skin! I will shrivel you from tail to snout, if you come within this ring" (2.4.42).
The wolf leaps forward, but Legolas shoots it with his arrow.
The wolves pull back and the darkness grows silent.
Suddenly, a huge pack of Wargs – evil wolves – attacks them from all sides.
Gandalf fights the Wargs back with fire, and by dawn, they have all been beaten back.
But in the morning, the Company discovers that there are no wolf bodies left; Gandalf is sure that these are no ordinary wolves.
They must race to the doors of Moria before sunset.
At last, they reach Sirannon, the Gate-stream, and the dry remains of the Stair Falls.
Gandalf mutters to Frodo that they cannot take Bill the pony into the mines; even though it will sadden Sam, they will have to set Bill free.
The sun is setting as they reach the end of the Elvish road from Hollin to Moria.
Near the doors, there is a green and stagnant lake.
Gandalf breaks the news to Sam that they cannot take Bill with them; Sam bursts into tears and unloads the pony.
Gandalf goes to the rock face and mutters a few words.
In the light of the moon, a door shines out from the wall.
The door says: "The Doors of Durin, Lord of Moria [...] Speak, friend, and enter" (2.4.98).
Gandalf decides that there must be a password, so he tries many words and incantations to try to get inside.
The doors remain stubbornly shut.
Boromir picks up a stone and throws it into the scummy pool near the doors.
Frodo scolds Boromir for disturbing the water.
Finally, Gandalf gets it: say "friend" and enter. He says the Elvish word for friend, mellon, and the doors crack open.
As the door opens, Frodo feels something wind around his ankle and pull him down.
Bill the pony bolts.
Huge tentacles are whipping out of the water, and one of them is dragging Frodo down into the pond.
Sam slashes at the tentacle holding Frodo and pulls him to safety.
Gandalf shouts at them to get inside.
The Company makes it through the doors just in time to see "many coiling arms [seizing] the doors on either side, and with horrible strength, [swinging] them round" (2.4.130).
The door is shut and blocked behind them.
Gandalf leads them down into Moria; it will be at least forty miles to the eastern gate and Dimrill Dale.
The Company does not dare use their torches, so they have to trust to Gandalf's memory to avoid deep crevasses and rock falls.
The journey is quite miserable.
Frodo in particular feels on red alert: ever since his injury with the Morgul-blade, his senses have been unusually acute, and he feels hyper-aware of danger ahead.
Frodo hears something padding behind them, something on soft feet.
Finally, they reach a crossroads that Gandalf does not remember.
They settle down to wait for a bit in a nearby guardroom; there is a deep well that seems to fascinate Pippin particularly.
Pippin throws a stone in the well and listens for it to land with an echoing plunk (2.4.160). Gandalf once again scolds him for making a nuisance of himself.
But then, deep in the mines, there comes a tapping sound, like some sort of signal; Gimli identifies it as the sound of a hammer.
The Company sets watch and goes to sleep.
Gandalf sits smoking for six hours until he decides what to do. In the end, he decides to take the right-hand passage, and the Company climbs up and up for eight hours.
Finally, the Hobbits are too tired to go on, and they decide to rest for the night.
Gandalf guesses that they are now actually a ways above the Dimrill Gate.
He risks enough light to see where they are.
They find themselves in a huge empty hall: "its black walls, polished and smooth as glass, [flash] and glitter. Three other entrances they see, dark black arches, one straight before them eastwards, and one on either side" (2.4.176).
Gandalf puts out the light, but Gimli is moved to sing a song of Moria in Durin's day. Naturally.
Sam asks why the Dwarves came back to Moria.
Gandalf answers: mithril. Mithril is a spectacular metal that is light and yet harder than steel.
He mentions that Bilbo had a coat of mithril mail, which would have been worth more than the Shire.
Frodo feels a bit alarmed that he is currently wearing the worth of the Shire hidden under his clothes.
The Company goes to sleep, and when they wake, it is morning – really morning, because there is light coming in from somewhere.
Gandalf predicts that they will come to the Great Gates and the lake of Mirrowmere by the end of that day.
Gimli is glad: he is happy to have seen Moria, but it has become a dark and dreadful place.
They go toward the light beyond the northern archway and find a dimly lit square chamber. In it is a slab of stone that reads, "Balin Son of Fundin, Lord of Moria" (2.4.201).