[Pervinca Took]

BYWATER: Battles are now mostly internal. Except for this one.
ORODRUIN: It reeled, it belched; the Ring was squelched.
OVER: Describes the Third Age, by the final sentence.
KINGS' NORBURY: As foretold, the crownless becomes it. But add a sleepy town and end up here? Sounds like it!

V: Wrecker, starting on igloo and/or its library? All very confused. Mentioned in lineage, to stake a claim.
IORHAEL: He goes where they might call him this? Perhaps unlikely, perhaps not – but an apocryphal letter will thus address his namesake.

Frodo is in Book VI, and so is his 'going' to the 'where' of the clue. That'll do, surely? I think I've probably used Incanus or Envinyatar, etc, in books where they weren't specifically called that or said to be sometimes called that.

'By' is 'by the time of the last sentence,' just as 'by November' is 'by the time it's November.'

Tolkien actually says Orodruin reeled. And belched. It's a very rude volcano!

And Norbury of the Kings is mentioned to Barliman by Gandalf on the way home, (well, home for the hobbits). I used the slightly different form because I needed the K. Originally, though, the answer was just KING and the clue only consisted of the first sentence - which still worked for Book VI.

I thought Orodruin would be the first clue to fall!

One to go!