I enjoyed the story and thought the horror imagery was handled well. The characterizations were a bit weak, though. Ellie's transition from whiny brat to dedicated little sister happened so quickly, it almost seemed to take place between chapters. Circumstances may have been extreme, but I'm not sure that makes much sense. The same thing happened to Alex later on in the book. Once she was in a different setting, traits that had until then ensured her survival disappeared and she became someone totally different. Other characters—even important ones—were like ciphers. Still, zombies are fun, and I'll probably read the next two in the series.