I have to agree with one of the earlier reviewers that this would have been a better book if it had stopped halfway through. In the first half, we are introduced to the eerie world of the Invisibles from the perspective of the young Jack Frost protagonist, with whom we can relate (obnoxious as he might be).
But the second half of the book suffers from jarring time travel sequences, high gross-out content, arcane conversations, and a lack of sympathetic characters. The Marquis de Sade is, I think, *intended* to be such a viewpoint character, but I found him too strange and off-putting to have much sympathy for him. And the Invisibles themselves already seem to know everything.
That said, I have to conclude that it's a very ambitious and engrossing book nonetheless. The high point for me was Jack Frost's initiation to the Barbelo and whatnot, at the end of the 4th chapter. That had me really hooked, despite the fact that things got less interesting as the story went on.
I can definitely recommend this book to people who liked THE ILLUMINATUS! TRILOGY and some of the more paranoid Philip K. Dick novels; that sort of thing.