To Green Angel Tower was originally released as one huge
hardback book (over 1,000 pages long), but when it was reformatted for the
paperback edition, it was *way* too long to fit in a single volume. So the publishers had to split it in two, both volumes of which were longer than either of the other two books in the "
trilogy".
This book (or books, depending on which format you're reading) concludes Simon's adventures, and also his coming-of-age. A hell of a lot of loose ends are tidied up in the course of To Green Angel Tower, but some are left at the end, though it's doubtful that Williams will write about these characters again.
To Green Angel Tower starts off with most of the main characters gathered together at the Stone of Farewell; Simon is now a knight in Josua's service, and Josua finally has an army, of sorts, with which to start a campaign against Elias' and Ineluki's reign of terror. Following a hard trek from the marshy southlands, Isgrimnur finally returns to Josua along with Princess Miriamele; and with them is the hero Camaris, the greatest knight in living memory, long thought to be lost at sea. But they only have one of the three great swords, Thorn; Minneyar (Memory) and Jingizu (Sorrow) are still in the hands of the enemy. So, when he finds out that his beloved Princess Miriamele is setting off for the Hayholt, Simon pledges to defend her, and journeys with her to try to recover Minneyar from the burial mound of Prester John.
Memory, Sorrow and Thorn is probably my all-time favourite fantasy series. I think it was Locus magazine which descibed it as "The fantasy equivalent of War And Peace"... well, in terms of sheer length, as well as the number of characters, it certainly is that! But the great thing about it is that (for me, anyway), the number of characters is never confusing. There's just the right amount of background detail about each character to make them seem like real people, and they all make mistakes, or just fall flat on their asses, or are just plain fallible... Tad Williams is easily one of my favourite authors.
Considering its length, To Green Angel Tower is a pretty easy read. There's always plenty going on; Williams, as always, has at least two or three groups of characters running around at any given time, and changes between them every few chapters; sometimes to highten suspense, sometimes because of interdependencies between the groups, and sometimes just to keep everything up to date.
For more details, go have a look at www.tadwilliams.com, which has lots of comments by Tad on what he calls "the book that ate my life", as well as summaries of the rest of his books, and news of what he's currently up to. Or alternatively, go buy The Dragonbone Chair, and get reading!