Jack Vance's The Palace of Love is the third, and most luridly titled, novel in his Demon Princes quintet. Here, the protagonist turns his attention to Viole Falushe, whose notorious Palace of Love is the sybaritic front to his evil.
Interestingly, Vance has adapted the tone of each book in this series to fit the subject. The first book, dealing with a coldly logical and precise villain, was something of a logic puzzle; the second book, dealing with a dashing Romantic villain, was a rousing adventure story; and this third book, dealing with a voluptuary, has a feel of decadent languor.
Interesting, too, is that Vance seems to be advancing a plot solely in the intro quotes (taken from fictitious sources) to each chapter. These chapter quotes concern themselves with controversy over the Galactic Institute, which has successfully set itself to the task of limiting human progress for the sake of humanity's own good. Oddly enough, nothing else in the book touches on the theme at all, but it's pronouncedly present throughout the intro quotes. I'm wondering if Vance will develop the theme in the main narrative later, or if it's just an unusually thorough background detail.
At any rate, this book is pretty much exactly as good as its predecessors. If you've read those, you'll know whether you want to read this; if you haven't read those, you definitely don't want to read this.