It's a functional overview of the the world of spirits, combining an encyclopedic level overview with stats for the major types of spirits (apparations, djinn, angels, demons, ghosts, etc.) and rules for ritual magic. I give an unplaytested thumbs up to the ritual magic; it provides a nice low fantasy magic system for GURPS 3rd Edition. The stats for individual spirit types are a starting place for GMs, I guess, but are going to require a lot of tweaking for individual settings. The descriptive text approached the useless; it tries to cover angels, demons, fae, nature spirits, gods, Cthulhoid beings, ultraterrestrials and ghosts as understood by people at any point in time and space. There's little text on how to use these in gaming, and the descriptive text isn't going to help you much add spirits to a particular setting or game.

It's just too diffuse to be useful. If there were good text about how to use spirits in a roleplaying setting, it would be more useful, but as it is, it's now mostly good for some GURPS 3rd Ed. specific crunch. ( )