Heeding the advice of the wizard Gandalf, Frodo leaves his home, taking the Ring with him. He hopes to reach Rivendell, where he will be safe from Sauron, and where those wiser than he can decide what to do about the Ring.

In his journey he is accompanied by three hobbit friends, Pippin, Merry, and Sam. From the start they are pursued by Black Riders, the Ringwraiths who serve Sauron. Narrowly escaping these and other dangers and meeting other interesting characters en route (e.g, Tom Bombadil) they eventually come to Bree, where they meet Strider, another friend of Gandalf who leads them the rest of the way to Rivendell, through further hardships.

Book II chronicles Frodo's stay at Rivendell, where a plan is hatched to destroy the Ring in Mordor. Frodo sets forth with eight companions: two Men, Aragorn and Boromir, son of the Steward of the land of Gondor; an Elven prince, Legolas; Frodo's old friend and powerful wizard, Gandalf; Gimli the Dwarf; and Frodo's original three hobbit companions. These Nine Walkers were chosen to represent all the free races of Middle-earth and as a balance to the Nine Riders. They were also accompanied by Bill the Pony, whom Strider and the Hobbits acquired in Bree as a pack horse. Their attempt to cross the Misty Mountains is foiled by heavy snow, so they are forced to take a path under the mountains via Moria, an ancient Dwarf kingdom, now full of Orcs and other evil creatures, where Gandalf falls into the abyss after battling a Balrog. The remaining eight members of the Fellowship then spend some time in the elf-haven of Lothlórien, where they receive gifts that in many cases prove useful later in the quest. They leave Lórien by river, but Frodo begins to realize the Ring is having a malevolent effect on some members of the party. This book ends when Frodo and Sam depart secretly for Mordor and the Fellowship of the Ring dissolves.

Destiny
Behind the events that befall the Ring-Bearer and the Fellowship, the reader begins to sense, there lurks always a sense of Destiny, and in the end, it will be a concatenation of the effects spawned by the nature of Good itself, that undoes Evil. Frodo says of the ring's slave, Gollum, "What a pity that Bilbo did not stab that vile creature, when he had a chance!" and Gandalf's response is

"Pity? It was Pity that stayed his hand. Pity, and Mercy: not to strike without need. And he has been well rewarded, Frodo. Be sure that he took so little hurt from the evil, and escaped in the end, because he began his ownership of the Ring so. With Pity."