I really wish there were more authors like Tad Williams. He has spent three very long books slowly building up a fantasy epic to its climax, and at last the many different forces around Shadowmarch are about to clash. "Shadowheart" takes a LONG time to work its way to the climax, but it's still a brilliant, wrenching finale. 
 Picking up where the last book left off: Briony and Prince Eneas are leading a ragtag army to the castle, and the exiled Barrick is struggling with the effects of the Fireflower in a Qar citadel. And no sooner has Barrick recovered than he and the Qar queen Saqri set out on a journey into the gateways of the gods and the worlds of dreams, so that they can make their way to Shadowmarch. 
 Unfortunately, the Autarch Sulepis and the treacherous Tolly have virtually seized control of Shadowmarch Castle, and are planning to (separately) awaken gods for their own power. Allies and family are killed, treachery is unveiled, and the most terrifying enemy imaginable is about to attack all of them... 
 Like his Otherland and Memory, Sorrow and Thorn series, the Shadowmarch series expanded into a quadrilogy when the third book got too huge to actually be printed. Fortunately, this doesn't really throw off the balance of the book, since it merely feels like the last chunk of a vast, epic story. 
 And Williams' writing is sublime -- he twines together a dozen-plus plot threads into a shimmering, atmospheric tapestry. His prose is lush and almost dreamlike, and full of vibrant descriptions ("vines that bore nodding black flowers and leaves as purple as a bruise"). Actually, this book has some of the best writing I've ever seen from Williams -- the scenes where Barrick drifts through the misty fields of the dreaming dead are just exquisite. 
 But on the downside, the beginning is a little draggy (especially since it takes forever for Briony to actually do anything). And at the end, Williams is a little hasty in wrapping up some of the plot threads, like the ones about Anissa or Flint. 
 Williams further develops his massive cast -- a strong-willed princess, her tormented brother, a strange little boy, doughty Funderlings, ethereal Qar royals, and a runaway concubine -- and gives them all distinctive personalities. What's more, some of them evolve in very unexpected ways, but they all are stronger and better for the experience. Some of the conclusions are kind of unsatisfying (Quinnitan), but most of them are quite nice (Briony, Barrick). 
 It's kind of slow at times, but "Shadowheart" is a satisfying grand finale to Tad Williams' richly-imagined fantasy series. Compelling, powerful and beautifully-written.