Anyway, I think it makes some sense, but I'd love to hear your thoughts on it.
Oh, right: spoilers. Of course. They're in there. There was a second half, but I think it went a bit beyond a horse's understanding. Might try writing it again, but from Dormin's point of view this time (wish me luck!).
Purpose and Understanding
When he stood in front of the altar--when his fate was taken by the darkness like a petty prize--the Wanderer was not alone. Through all his travels, the lost soul had a friend. When the empty shell of a man was carried back to the Temple after each abomination was done, the first sound he would hear upon rising would be the voice of his Doom--but the second sound he heard would always be the quick beating of hooves as his one true companion returned to him.
The horse understood few things. He understood Loyalty, Water, and Grass. He did not yet understand the Shadow that covered the cursed land, but he was aware of it.
The thing the horse understood best of all was Purpose. His master's Purpose was to slay the beasts, however dark and ill-fated that Purpose was. The horse's Purpose was to carry his master.
So, then, when the horse bore his half-damned and battle-weary master into the great castle on the coast, his understanding was limited to one thing: carrying his master. When the horse saw that his master wished to cross a high bridge, the horse understood that his Purpose was to get his master to the other side.
When the bridge crumbled beneath his hooves, the horse understood Fear--but the Purpose remained. He threw his master and--"Agro!"--heard his voice for the last time.