Ig Perrish wakes up one morning with a hell of a hangover and discovers that he has grown horns on his head. He has become a (the?) devil, has powers and thus opportunities (but also downsides) he didn't have before, and within a short time, he knows just what he wants to do with them - take revenge for a hideous wrong. How best to do it?
That's simple enough, an amusing premise for something of a supernatural thriller, but Joe Hill does more than just exploit that - a lot more.
First of all, the book is just crazy funny. Hill has a great ear for dialogue, his scenes are often completely absurd and yet somehow believeable, and the situations are, after all, ridiculous on their face, but he makes it all work.
Second, his plotting (for such a strange book) is tight. The heart of the book is something of a murder mystery, and Hill uses flashbacks from various characters to good effect, putting the pieces of the puzzle in place in a pretty clever way.
Third, there is something more than just a wild ride for his characters here - there is actually a touching love story, and the revelations behind various motivations and actions are really well done. The last 50 pages or so, and especially the last 20, are in fact just downright intimate - and all without seeming mawkish or losing the flavor of the very strange ending.
It's a crime story, a horror story, a love story - frankly, it's a lot like something Steven King would have written 20 years ago. It's excellent.