Angels have descended down to earth but they're not the heavenly creatures people may have expected. Ruthless and lacking any trace of humanity, the Angels are ruling the world and treating humans no better than animals. When an angel takes her little sister Paige, Penryn plans to do the unthinkable. She wants to go into the Angels' aerie - their home base - to save her. With an injured angel, Raffe, as her guide, Penryn tempts fate to save Paige and bring what's left of her family back together. 
 I can understand why this book was an Internet phenomenon. Penryn is such a strong character. The angels have ruined the world. Millions are dead, modern civilisation all but demolished but there are still a few humans left struggling to exist in this new angel ruled world. In a post-apocalypse California, Penryn has been learning how to survive and taking over the parent role in her family. Her mother can not be relied upon for anything and has some strange ideas. But Paige keeps Penryn from getting too serious. Paige, although in a wheelchair after an incident when she was younger, would give up everything she had to help someone else. Penryn needs her little sister and when she's taken, Penryn risks life and a fate worse than death to bring Paige back. 
 This is a book with a quest, deadly angels, magical weapons and characters I adored. Penryn is intelligent and focused - if not a little too single mindedly obsessed - with getting her sister back. The angels are ruthless and I loved how different they were from how I usually imagine angels. These angels are beautiful and breathtakingly formidable. They murder humans and think nothing of it. But they're not invincible. They have politics of their own and a hierarchy that may not be as stable as the humans may believe. I liked Raffe the angel. He's every bit as intimidating as his fellow angels but due to circumstances beyond his control he finds himself having to rely on a human. The dynamic of Penryn and Raffe was great to read and I enjoyed the lack of an overt romantic relationship between the two. 
 I really enjoyed this book and for me it lived up to the hype. The gorgeous cover, brilliant take on angels and a heroine who I wanted to read more about. The second book in the series, World After, was released a few weeks ago and I can't wait to immerse myself once more in Penryn's world.