By the end of I Am Not a Serial Killer John Cleaver, teen psychopath with a heart of gold, had allowed himself to unleash the monster within just long enough to defeat the demon that had been plaguing John's small hometown. As Mr. Monster opens, six months later, John has been working extra hard--with the unwanted but enthusiastic help of his mom--to follow the rules he long ago created to help him tamp down the killer inside him (which he's dubbed "Mr. Monster"). He's afraid to go to sleep at night because of the nightmares that plague him, but he does get an awful lot of reading in.
He's even making tentative stabs at normality, using the clunker of a car his mom got him to drive Brooke, the girl of his nightmares dreams to school everyday. Of course, his rules are so elaborate that he doesn't even allow himself to look at what Brooke's wearing when she's sitting beside him in the car (because when he does he can't help but remember those nightmares, in which he has her on a slab in the family mortuary), but it's a start.
But bodies will start piling up in small towns with an attraction for serial killers (supernatural or otherwise), and once again, here they are. Young women, this time, strangers to the town, but definitely dead...and horribly abused before their deaths. John, who's been called regularly into the office of FBI Agent Forman who has for some reason set up shop in town after the killings of the previous year, is once again intrigued; on one of his visits for "follow-up" questioning he attempts to elicit information from Forman, who is surprisingly forthcoming.
Dan Wells has written a sequel which is every bit as good as its predecessor. In fact, though John's investigations into the killings and subsequent discovery of the killer are good--particularly the climactic sequence, which involves prisoners, torture, and a woman bricked up in a wall--what's even better is Wells's peek into the mind of an adolescent boy struggling simultaneously with his first real crush and keeping his psychopathic inner self under control.