So, I've read The Silmarillion several times now, and I can't figure out one thing: Just how did Ëarendil defeat Ancalagon?
Tolkien is very vague on this: Ëarendil flies in with Eagles to battle dragons, the fight ensues (with Ëarendil flying around the outskirts, glowing, and roaring his heart out with lethal encouragement?), Ancalagon enters, Ëarendil shines with "white flame", and Ancalagon is.... um... dead.
(Enchanted) arrows and/or bolts of "Vala-lightning" are what I assume he used. But I can't be sure. For all I know he could have impaled Ancalagon with a sharpened prow, jumped off, slit the dragon's throat, and backflipped to the safety of Vingilot.
This is one of the most disappointing scenes in all of Tolkien's writing for me. Here had a chance to write about a terrific smash-up, and he reduced it to: Ëarendil shows up, Ëarendil glows, Ancalagon dies. I wish Tolkien had been more descriptive in this passage like he was about the battle between Fingolfin and Morgoth.