This epic series of modules was originally written for the World of Greyhawk by Gary Gygax's co-DM Rob Kuntz. Rob Kuntz published credits also include the original "Greyhawk" supplement, "Gods, Demigods & Heroes," "Legends and Lore," "Mordenkainen's Fantastic Adventure" among others. This series was originally set in the Great Kingdom as the party prepares to assasinate King Ivid the Mad but soon discovers the archmage Xayene is at the root of the King's madness. Soon the characters find themselves desperately trapped in the labyrinthine wake of Xayene's web of deceit.
After leaving TSR to found Creations Unlimited, Rob Kuntz took this Greyhawk module and transferred it to his own campaign world of Kalibruhn. To protect his work from TSR he changed the game statistics and names, e.g., King Ivid is King Ovar, Xayene is Zayene, etc. All are minor changes that can easily be altered to transport these modules back to their proper setting. The statistic and spell changes are pretty minor and are identical to Advanced Dungeons & Dragons in most respects.