The battle between darkness and hope...summed up perfectly by Samwise Gamgee:
It's all wrong...we shouldn't even be here.
But we are.
It's like in the great stories, Mr. Frodo, the ones that really matter. Full of darkness and danger they were. And sometimes you didn't want to know the end because how could the end be happy? How could the world go back to the way it was when so much bad happens?
But in the end, it's only a passing thing...even darkness must pass.
A new day will come. And when the sun shines it will shine out the clearer.
Those are the stories that stay with you.
But I think, Mr. Frodo, I do understand.
I know now folks in those stories had lots of chances of turning back, only they didn't. They kept going. Because they were holding onto something...
That there's some good in this world, Mr. Frodo, and it's worth fighting for.