The Face by Jack Vance

I don't want to say that Kirth Gersen has fallen into a groove - or that the novels about him have - but there are similarities to all of his pursuits of Demon Princes to this point. His targets are all monomaniacs, not just criminals and ganglords but obsessives about specific things, cruel and mercurial in their temperaments and demanding that things be done their way all the time. They also all hide as other people, concealing their true identities behind masks when traveling through the civilized galaxy, only revealing themselves fully in their lawless homes of the Beyond.

Also common in multiple books: Gersen tracks them, one by one, partially by using the fortune he made in the second book, The Killing Machine. He worries both that he's losing the edge that gives him a chance to find and kill these monsters, and that he's forever unable to have a normal human life because of that edge. He meets women he's attracted to - in this book, as in the last two - which brings that contrast more strongly to his attention. He wants to find love, to live like a normal person...but he can't let himself do that.

Not while any of the Demon Princes still live. He was made into a weapon by his grandfather, and that weapon needs to be used fully before it can be put away.

The Face is the fourth of the novels: it followed The Star King, The Killing Machine, and The Palace of Love. The novel itself takes place what we think is soon after the previous books: it's never quite clear how much time is passing in this series, but it's not very long: maybe a few years, beginning to end. But the book came twelve years after its predecessor - readers in the real world at the time might have wondered if Vance would ever come back to the Demon Princes and finish the series.

(He did, obviously. My memory is that personally I only started reading Vance around the time of the last book, in 1981, so for my entire relevant reading life, the Demon Princes was a series complete.)

The fourth Demon Prince is Lens Larque, a sadist fond of tricks and schemes, a man from the cruel mostly-desert world Dar Sai and whose way of viewing the world - Vance does not emphasize this, but makes it clear as the novel goes on - is that of his people, only in exaggerated, hair-trigger form, just like them only more so.

Gersen spends the novel tracking the purpose and history of a now-worthless mining company that Larque controls through intermediaries, as always looking for a way to find the man he's chasing, to get close enough to kill his target. Along the way, he spends time on Dar Sai, gaining control of that mining company and learning more about the Darsh people, and then on Dar Sai's sister planet Methel, a richer, more comfortable world that hates and is hated by the Darsh in the way of neighboring nations everywhere.

Of course, Gersen does find Larque, and does kill him. That's the plot of the series. But the hunt is the point - both how Gersen has to figure out the aim of that seemingly useless mining company, how he gathers the supposedly worthless shares of that company to take it over, and all the things he learns about Larque and the Darsh along the way.

And now there is only one left: just one Demon Prince, the leader and organizer of them all. And Vance would get to his story much more quickly than he did to The Face, just a couple of years later. 

(Consumer Note: I linked The Face to the current standalone edition, a hardcover published by the Vance-family-controlled Spatterlight Press. That's certainly a solid choice, but the book is also available in a cheaper omnibus edition, The Demon Princes, Vol. 2, which is how I read it.)