From the back cover:
Clerics have long been players' favorites, but now there are new priest characters for your gaming enjoyment! Within these pages are new rules for mythos-specific priests, guidelines for creating mythoi of your own, how-to's for making new priesthoods. Also here are new Priest Kits, so you can play a fighting monk, an amazon priestess, a savage priest, or even a peasant priest (among many others). All this and more is presented in these 128 pages, the newest accessory for players and DMs.