Tight and very square - obviously unread. The only flaw to DJ is a faint 3" scratch in top/middle of back cover which follows the artwork (will not show in scan / best seen by angling the book to catch the light just right.)

omnibus of: THE STAR KING (1964) + THE KILLING MACHINE (1964) + THE PALACE OF LOVE (1967) + THE FACE (1979) + THE BOOK OF DREAMS (1981.) This is huge: 964 pages / 1-3/4" thick.

Kirth Gersen had a mission of vengeance: to track down the five "Demon Princes" who led the Mount Pleasant Massacre - where Gersen's family and and world were destroyed. The Demon Princes are of a race of beings who disguise themselves as humans and delight in power and destruction.

The Killing Machine - the 2nd book in the "Demon Princes" series. Gersen carried a slip of paper with their names on it in his pocket - last on the list was Kokor Hekkus (The Killing Machine.) Now Gersen was hunting him down. Wanted on every planet in the universe by law forces too terrified to attempt his capture, Kokor Hekkus loved intricate, malevolent mechanisms. Out beyond the Dog Star, Gersen and Hekkus met and matched wits on legendary Thamber, where the Demon Prince had constructed his final and most frightful Killing Machine.

A bit of trivia about the original publication: this was originally slated to be serialized in IF at the beginning of 1965, but the paperback publisher jumped the gun. So IF apologized, changed the serial, and ended up using the cover intended for The Killing Machine for Starchild.

The Palace of Love - the third book in the "Demon Princes" series. Wealthy and unrelenting, Gersen spares no expense as he journeys from the sinister planet of the poison-masters to the slave-city of Sabra to learn the whereabouts of his quarry: Viole Falushie. Gersen tracks down the elusive Falushie at the strange pleasure temple known as the Palace of Love, where at last their deadly confrontation takes place. This was serialized in Galaxy October & December 1966, and February 1967.

The Face (1979.) Gersen runs into Lens Larque: personally ugly, startlingly vicious, and arrogant above all others.

The Book of Dreams (1981.) Gersen tracks the last of the Princes, Howard Alan Treesong: who poisoned his friends, tortured his colleages, and wrote his own holy book: "The Book of Dreams."