Book II, Chapter 4: "A Journey in the Dark"
Gandalf-with some reluctance but seeing no other alternative (save returning to Rivendell with the Ring in defeat, and sealing its eventual doom)-proposes that the Fellowship pass through the Mines of Moria. Balin's people may still populate the Mines, but Gandalf warns they may also encounter Orcs. At night, atop a small hill, the Fellowship is attacked by Wargs-wild wolves, servants of Sauron. The attack encourages the company to move swiftly to the doors of Moria./p>
At the gates of Moria, Gandalf sends Bill the pony back to Rivendell with words of blessing. Sam is sad to see Bill go, and the pony's departure means the members of the Fellowship must now bear more of their burden themselves. Gandalf is at first unable to open the enchanted door to Moria. Their legend reads: "Speak, friend, and enter." The wizard tries many spells before realizing that the solution is simple: he must speak, not a secret password, but simply the Elvish word for "friend." As soon as he does, the gate opens, and the company begins to pass through. At that moment, a tentacle from a lake outside the gate grabs Frodo's ankle, soon followed by twenty more. Sam stabs one of the unseen beasts tentacles, and it lets Frodo go, using its arms to close the door to Moria behind the Fellowship.
Led by Gandalf-and, to a lesser extent, by Gimli, who has been eager to enter Moria-the Fellowship begins its dangerous descent into the mines. Frodo notes effects of his wound: he can see more clearly in the dark than anyone but Gandalf, and his hearing is sharper as well. He hears "the faint fall of soft bare feet" following the company. Later in this chapter, as he takes a watch during the night, he sees "two pale points of light, almost like luminous eyes." By these details, Tolkien is again preparing readers for the introduction of Gollum in Book IV.
The Fellowship halts at a fork in its path at which Gandalf is unsure how to proceed. While waiting, Pippin drops a stone into an ancient well. Gandalf rebukes the Hobbit for making such noise, which is shortly answered by knocking from the depths.
At length, the Fellowship presses on. Gimli and Gandalf, conversing about Moria's former glory, happen to reveal that the material of which Frodo's secret chain-mail is made, mithril, is a priceless treasure coveted by Sauron. Gandalf mentions Bilbo's old treasure, that the coat of mail had "worth greater than the value of the whole Shire and everything in it." This knowledge does not bring any comfort to Frodo!