I think this was my favorite of all of the Riders of the Apocalypse books that I have read. Billy Ballard is the victim of persistent and sustained bullying and just wants to get through the day. When Death comes calling and says he has to stand in as Pestilence, Billy feels totally unqualified and out of his depth. But he made a promise when he was five-years-old to a man who has haunted his nightmares ever since and he is stuck with the job. The job is made even more difficult by the fact that Pestilence is insane. We see the history of Pestilence who began life as King Mita of Phrygia and who took up the crown of Pestilence upon the death of his beloved young daughter. This Pestilence has served for thousands of years and the horrors he has seen and caused have made him insane. He is determined to end the world once and for all. Billy has to dive into Pestilence's memories and face his own fears before the world can be saved.I love the language in this story. The descriptions made me feel like I was there with Billy which was not exactly a good thing when he was being tormented by the bullies at his school. The only downside that I could find for this story was that Death didn't make enough appearances. There was less of the quirky humor that Death brought to the earlier books in the series. This book deals with real life issues like bullying and like caring for a grandparent with Alzheimer's. I thought Billy's feelings about his grandfather were very realistic as he switched between remembering the grandfather who was such a central part of his childhood and resenting the responsibility for caring for this sometimes violent stranger his grandfather had become. I agreed with him when he felt that he had too much irresponsibility for a fifteen-year-old. I also really resented the mother who didn't see that her son was being bullied and the school system that didn't see it either. This was an excellent story about a young man who doesn't let an impossible situation defeat him and who struggles with both grace and courage. I thought that the ending was realistic and not a typical "they all lived happily ever after." I recommend this story to all young adults.