Interesting premise and entertaining quick read, but this left me with less of an impression than other recent Shusterman books.
Nick and Allison die in the same accident and knock each other off the path to the light. They wake up still on Earth, but stuck on the ghostly side. They discover there are others - lots of others, and they're all under 17. Gangs form, sides are taken, monsters are fought and discoveries made.
Interesting, mildly creepy young YA action. I'm reading the sequel, but I almost stopped after this first book because I was entertained but not really all that invested in spending more time with the characters and story world. But the blurb for book 2 had a good twist, so I'm going to keep going. I should stress that it's not at all a bad book, just a matter of taste, I think.