Book II, Chapter 10: "The Breaking of the Fellowship"
Aragorn confronts the Fellowship with the choice they must now make: to go with Boromir to Minas Tirith, to travel with Frodo into Mordor, or to travel their separate ways. When no one speaks, Aragorn asks Frodo to choose. Frodo asks for an hour of time alone in which to make his decision. As Frodo departs, Sam notices that Boromir is watching Frodo intently.
Boromir follows Frodo and tries to counsel him, although Frodo already knows what advice Boromir will give. Boromir asks to see the Ring; Frodo refuses. Boromir attempts to make light of the refusal, yet he tries to persuade Frodo that the Ring could be used to defend Minas Tirith. He claims that he would be strong enough to prevent what he does with the Ring from becoming evil. He rails against what he perceives as the folly of the Council's plan to send Frodo into Mordor to destroy the Ring. Boromir grows more impassioned in his speech, and thinks he has convinced Frodo to come with him, at least for a while, to Gondor; when Frodo does not respond, Boromir attempts to take the Ring from him by force. Frodo puts on the Ring and vanishes. After a moment, Boromir realizes the wrong he has done, and he calls for Frodo's return. The Hobbit does not reappear.
Frodo runs to the summit of Amon Hen, still wearing the Ring. "[E]verywhere he looked he saw the signs of war . . . . All the power of the Dark Lord was in motion." Frodo also feels the Eye of Sauron looking for him. Within himself, Frodo hears competing voices: "Never, never!" and "Verily I come, I come to you." Yet he also hears "from some other point of power" a voice telling him: "Fool, take it off! Take off the Ring!" (Might Tolkien be hinting at this point that Gandalf did not perish as he appeared to?) Frodo chooses to remove the Ring, and resolves to go to Mordor by himself, since the Ring's evil is tearing the Fellowship apart. Yet, as he seeks to escape the others' notice, he replaces the Ring on his finger.
The others, for their part, are in fact wondering why Frodo has delayed so long. Legolas suggests that they call Frodo back for a vote to help him decide. He and Gimli would vote for Minas Tirith, but only if Frodo would, as well; otherwise, they would accompany him to Mordor. Aragorn decides that not all of the company should go with Frodo; only Sam, Gimli, and himself. He suggests that Boromir go to Minas Tirith, along with Merry, Pippin, and Legolas. Merry and Pippin, however, object to leaving Frodo. When Sam states that Frodo would have no need to go to Minas Tirith, the Fellowship notices that Boromir is not with them. Soon, he returns, but he does not tell the others the whole truth of his meeting with Frodo; he says only that Frodo grew angry with him and vanished. Despite Aragorn's attempts to organize a search, the others dash off in search of Frodo. Aragorn charges Boromir to go after Merry and Pippin and protect them, for he fears Orcs are close at hand.
Sam, having fallen behind Aragorn, realizes what Frodo's plan is, and finds Frodo back at the boats. A boat seems to be moving by itself. Sam plunges into the River after it, only to begin drowning. Frodo pulls him out of the water and removes the Ring. Over Frodo's objections, Sam announces that he will go with him to Mordor. As they move down the River, Frodo supposes they will never see the other members of the Fellowship again. Sam holds out hope that they may. The two Hobbits reach the River's far shore, hide their boat, and begin seeking a way into Mordor.