Elliot and his friends go on a cave expedition. There is a crazy earthquake, and then, suddenly they all wake up to a whole different world then the one they left. Everything is destroyed. It's a post-apocalyptic world and they have to learn how to survive and thrive in this new terrain. There are gangas (zombie-like creatures that only move around at night) that they have to avoid, wild animals everywhere, and small settlements.They run into a girl named Jade who takes them to Envy, a large settlement, where they find some shocking discoveries about what has been happening during the 50 years that they were "asleep" in that cave. Elliot, Jade and all the others must go on a crazy journey. But maybe they can find their place in this crazy new world, if they can all survive.This book was exciting, full of action from the first page to the last. I really enjoyed it and the characters of this scary new world.