The Return of the King
How we cite our quotes:
And so it was that Gwaihir saw them with his keen farseeing eyes, as down the wild wind he came, and daring the great peril of the skies he circled in the air: two small dark figures, forlorn, hand in hand upon a little hill, while the world shook under them, and gasped, and rivers of fire drew near. And even as he espied them and came swooping down, he saw them fall, worn out, or choked with fumes and heat, or stricken down by despair at last, hiding their eyes from death. (6.4.23)
There you have it, folks: the emotional climax of the entire series. Sam and Frodo, standing on an island in the middle of a sea of lava, wait for inevitable death. They don't protest this death or try to resist it. They just wait. Instead of giving us a whole huge battle scene with the hordes of Mordor versus Aragorn and his guys, Tolkien shows us the true battle behind the scenes—Frodo and Sam versus, well, evil. And now that they have absolutely submitted themselves to their fates, the unlikeliest thing comes to save them: Gwaihir the Windlord and Gandalf, whom Frodo and Sam still believe has died (see 6.3.5). Sam and Frodo's humility in front of fate contrasts completely with, say, Denethor's dramatics or Sauron's attempt to control the whole world. This willingness to keep trucking as long as they can, no matter what fate throws their way, until they can't keep going any longer, is what makes them morally great in Tolkien's world. Their perseverance makes them heroes.