This is the completion of the Majipoor trilogy involving Prestimion (Sorcerers of Majipoor and Lord Prestimion). Silverberg says this will be "probably the final Majipoor book." And, much as I love the big planet, I can't blame him for wanting to move on.
Lord Prestimion has reigned for twenty years, and Confalume Pontifex is getting very old, which means the inevitable move from Castle Mount to the Labyrinth will come soon. After a long and prosperous rule (barring the difficulties detailed in the first two books), Prestimion is ready to move on, and Dekkeret is ready to assume the Starburst Throne. But trouble is of course brewing, and it follows from the earlier conflicts, since that nasty Count Mandralisca managed to escape the fate of his master.
Unlike Lord Prestimion, which started a bit slowly, this one gets going pretty quickly. Chapters alternate between a number of characters, including Prestimion, Dekkeret (the Coronal-apparent), Thastain (a young man in the service of Mandralisca), Varaile (Prestimion's wife), Mandralisca himself, and others. All are vivid and captivating, and Silverberg (as usual) gives even the hideous Mandralisca a measure of depth, with a tragic childhood dominated by an abusive alcoholic father. One of my favorite characters is Keltryn, the younger sister of Dekkeret's lover Fulkari, who comes to the Castle and starts fencing lessons with Septach Melayn.
SciFi.com published a review in their Issue #222.