The story progresses step by step, cutting back and forth between the two desperate, nearly powerless elves struggling along with the magical tree seed towards their perilous destination while fleeing the deadly Nazgul. I mean Reaper. Meanwhile the other plot has a great battle where the elves try to hold off the vast hordes of besieging orcs at Helm's Deep. I mean demons in the elf city.
Will the elf and the chosen elf get the seed there in time? Will they find some way to return to the elf city just before the demonic hordes overrun it? What do you think? There's even a huge falcon to fly them to the rescue when all hope appeared lost.
...My main complaint about the plot, besides the LotR familiarity, was how convenient and silly it all was. Every time the two lone elves were screwed, they were saved by some incredibly convenient occurrence. A river god who hadn't been seen in a thousand years would sweep them up, or a gypsy they'd met earlier would reappear to pull them to safety just as a mob of thieves were about to kill them. Or a pair of witches they couldn't possibly defeat would suddenly kill each other fighting over them. Or the one person on earth who knew how to guide them to their destination would appear when they had no way to advance (this happened twice).
A few lucky breaks are necessary in a fantasy quest adventure like this one, but there must have been 6 or 8 incredible strokes of luck just in the one quest story line, and I was rolling my eyes by the 4th or 5th time they were stopped with no hope, knowing that the next chapter would bring yet another saving miracle.