** spoiler alert ** 
 Finders Keepers, the second book in King's Bill Hodges trilogy, was nominally the sequel to Mr. Mercedes. Certainly it is the sequel in the Bill Hodges timeline. End of Watch, however, is the true sequel to Mr. Mercedes, and the ending of Bill's story. 
 End of Watch reunites the Mr. Mercedes team - Bill Hodges, retired cop, Holly Gibney, computer whiz with OCD, and Jerome Robinson, high school student now attending college - against Brady Hartsfield, the man who brought them together. The first book of the series was a straight-up thriller; this book travels firmly into the author's home territory. Our pal Brady received brain damage at the end of the first novel that should have put him in nursing care for life, but a neurologist decides that he wants to try an experimental treatment on the hush-hush with the crippled spree killer. Now Brady's body is still a wreck, but he has new psychic abilities. They let him drive people to suicide, and he relishes it. 
 Bill and Holly are still running their "not-a-detective-agency" detective agency, and Bill is called to consult on one of the suicide cases because of its ties to the Mr. Mercedes case. He quickly scents Brady's involvement, because he has always believed that Brady was faking mental incapacity. He pursues his suspicion aggressively, but Bill has a problem: he's dying of cancer. During his pursuit, he uses increasingly ineffective pain pills to keep going, and he lies to Holly about his health. Naturally, she is too smart and learns the truth, but she can either help him stop Brady or walk away. Jerome joins them when his sister nearly dies by Brady's mental pushing. The trio are pushed to their limits as they chase a man who can kill without touching, and flee from body to body. 
 King handles the action with his usual skill, but his gift has always been in characterization. His heroes read like real people, from their frailties to their taste in food, and they age and face new issues as King does. He's also begun to add new viewpoints from characters who are not like himself. In the first novel, Holly Gibney starts as a meek and neurotic woman still under her mother's thumb. She becomes integral in solving the Mr. Mercedes case and is the one who physically brings Brady down. In End of Watch, she still has her nervous tics, but she has pushed through them to run a successful business with Bill. She is a full partner in the investigation, and King tells the story sometimes from her viewpoint. At the end of the third novel, we see that with or without Bill, Holly is strong enough to make her way.