This is the third book in Stephen King's "Bill Hodges Trilogy."
In the first book, Mr. Mercedes, a sociopath named Brady Hartsfield drives a Mercedes into a crowd, causing numerous deaths and injuries. Retired detective Bill Hodges makes it his mission to nab the culprit and puts together a sort of ragtag team to do the job. This includes Holly Gibney - a thin, gray-haired computer whiz who probably has Asperger's syndrome; and Jerome Robinson - a black, whip-smart teen. The three 'partners' eventually form a tight, affectionate, and lasting bond. At the end of the book Brady Hartsfield is severely injured, with a brain injury that leaves him in a coma.
The second book in the trilogy, Finders Keepers, takes a different direction, focusing on an obsessed literary fan. Hodges and his team show up late in the story, to help a kid who's gotten himself into big trouble. Brady Hartsfield, meanwhile, is rotting away in a hospital - seemingly unaware of his surroundings, with minimal brain function. Retired detective Hodges, however, suspects that Brady might have more going on upstairs than he lets on, and - as things turn out - Hodges is right!
In this third book in the trilogy, End of Watch - which takes place five years after the events in Mr. Mercedes - Brady Hartsfield has come out of his coma, is somewhat aware of what's going on around him, and can even say a few muddled words. Physically Brady is almost completely helpless, but there's A LOT going on in his head.
Brady's unethical doctor has been giving him experimental drugs and the medicine (or maybe something else) has altered Brady's brain....and he now has paranormal abilities. The hospital staff notes that minor odd things happen in Brady's room - like his IV bag swinging back and forth - but no one has an inkling of his true capabilities.
Brady secretly puts this new talent to use using a cache of obsolete hand-held computer game consoles called 'Zappit.' As it turns out, Zappit contains a strangely hypnotic child's fishing game. I don't want to give too much away, so I'll just say Brady - who has an obsession about suicide - manipulates a few people into killing themselves. Thrilled with his success, Brady embarks on a plan to cause mass suicide among local teenagers. And finally, Brady means to completely destroy Bill Hodges, whom he REALLY hates.
The stakes are very high in this book. Hodges is seriously ill and Holly is on his case - insisting that he go to the hospital to get appropriate treatment. However the detective desperately wants to stop Brady first. Hodges is sure that Brady caused a number of recent deaths, but can't figure out how - since Brady is a decrepit husk sitting in a hospital room. It takes the combined brain power of Hodges, Holly, and Jerome - with some help from a cop and a spot of luck - to reveal exactly what's going on. All this leads to a doozy of a climax in the middle of a winter storm...very exciting!
I enjoyed the book, which is well-written with memorable characters. Brady makes an especially demented and evil villain, while Holly makes an endearing 'good guy', with sweet affection for her partner and friend, Bill Hodges. In fact Holly is probably my favorite character in this story.
This book provides a very satisfying finale to a good trilogy. Highly recommended.