But by the end of his quest in Mordor, he is just too exhausted to keep fighting. He fights the good fight for longer than any of the other characters could have managed (we're looking at you, Boromir). So, to make a long story short, eventually, even Frodo fails. It's not in the nature of Frodo-or any ordinary mortal-to fight all the time without stopping. He isn't built for a 24/7 struggle against the worst kind of evil. And the thing is, Frodo is only human-or rather, only hobbit. The pressure never stops in fact, it keeps getting worse and worse. It's always with him, even when he closes his eyes. Because the Ring is slowly starting to take control of Frodo's soul, he can never escape it.

To summarize this passage: Frodo in Book Three? Not in a good place. I begin to see it even with my waking eyes, and all else fades. I am naked in the dark, Sam, and there is no veil between me and the wheel of fire. No taste of food, no feel of water, no sound of wind, no memory of tree or grass or flower, no image of moon or star are left to me. It's really the worst kind of torture we can imagine, so we'll just let Frodo describe it for himself:

Everywhere he goes, no matter what he does, he can't hide from the evil of the Ring. But the worst thing about Frodo's own particular battle against evil is that it is also a struggle against himself.

Not to get too grim or anything, but The Return of the King is mainly about confronting different kinds of evil: the evil of emotional abuse (Denethor), the evil of bitterness and disappointment (Saruman), and the evil of greed (gosh, there are a lot of thieving orcs in this novel). (Click the character infographic to download.)

Lord of the rings gollum's death