This plot has been re-interpreted numerous times, most recently the House of M crossover event for Marvel. I also feel there's influence from the movie Inception and The Matrix with an episode of Star Trek: The Next Generation name checked for good measure. It's a good plot that changes every time it's used with different players. Why? Because it's a good plot and a great way to show off characterization.
Ex-Purgatory begins with Saint George a.k.a the Mighty Dragon working as a janitor at a local university. He is haunted by strange dreams but the world hasn't been destroyed so he's reasonably content. The mystery of what's going on occupies roughly 75% of the novel with the villain responsible revealed early but not the how. Ultimately, the book ends with an effective twist.
The book increases the role of Madelyn a.k.a Corpse Girl dramatically. Introduced in the previous volume, we get some more insights into her personality and ideas. Sadly, we don't get to know much more about her past. What sort of life did Madelyn live before things went to hell? What would she have preferred to do? We do get insights into just about everyone else, however, with Stealth's backstory being the most fleshed out. I'm not sure I cared for it but I trust Peter Clines knows what he's doing.
If I have any regrets, it's the fact Ex-Purgatory is a little too "safe." Ex-Heroes and Ex-Patriots introduced most of the concepts that have been used in this book and its predecessor. I'm eager to see something new and exciting. Unfortunately, this feels very self-contained and a little bit like a reunion special. The plot isn't moving forward and I'd very much like to see something radical happen like the discovery of another survivor settlement or a trip to the future.
We get some insight into the backstory of Stealth that reveals she's the daughter of a prominent Somali terrorist but this tantalizing bit of backstory is not something that gets much insight. I would have liked a lot more discussion of this as it helps change the character's Doc Savage-esque origin to something darker. How she was trained by her father and what purpose before she became a model as well as genius would have made a fascinating story on its own, even without the brainwashing element.
There's also the fact, for a zombie novel, it doesn't have that much in the way of zombies. The "Exes" make an appearance in the book at critical moments but feel almost like an afterthought. Despite the critical threat they posed in previous books, they're treated barely as a threat in Ex-Purgatory. While I wouldn't recommend going Walking Dead on the cast, I'd like to see them take center stage. The Exes are what separate this series from other superhero comics.
Fans of Ex-Heroes will continue to enjoy this new volume in the series but those who are looking to pick up the series should start earlier. Ex-Purgatory is a very continuity-reliant book and would be almost incomprehensible to a new reader. Still, I enjoyed it. The humor is sharp, the characters are likable, and the story allows them to show new sides of themselves. Unfortunately, this book suffers from the fact that not much progress is made in the storyline. It feels like the characters and the world are in the same place at the end of the book that they were at the beginning of it.