Fantastic book, it is a Storyteller supplement though so players will be disappointed if they come looking for new powers and merits (though there are new merits and Sin Eater related powers - 1 new Key and Manifestation, as well rituals). This book provides the ST with the information they will need to use the underworld in any New World of Darkness genre, the example Domains at the end of the book are especially helpful in outlining the scope of the Underworld. I would recommend this to any ST who intends to incorporate the Underworld into their game.