It's really, really important to remember that Mr. Mercedes is not a template -- it's not one of those Internet sites that explains step-by-step how to do something really evil using ordinary household items.
Because, in choosing to stick to an all-too-human monster for one of the very few times in a career of more than four dozen spooky novels, American author Stephen King just might be putting ideas in someone's head.
Mr. Mercedes is some of King's best work in a long time.
The novel is creepy, it's horrifying, it has engaging characters about whom the reader will come to care -- be careful about caring too much -- and just when it's obvious what will happen, King wallops the reader from the blind side with totally unexpected twists.
The titular character commits mass murder in the novel's first few pages and gets away with it. He will, it goes without saying, plot to do so again.
Mr. Mercedes is a novel that would be ruined by spoilers. Suffice it to say that King reveals the identity of the killer early on; a retired police detective named Bill Hodges, haunted by his failure to solve those mass murders, spends 448 pages trying to track down Mr. Mercedes before he kills again.
People are haunted in Mr. Mercedes, though for once with King, it's not literal. There's nothing supernatural, nothing alien, no time travel or slipping between dimensions in Mr. Mercedes.
It's been a long time since King has gone with nothing but human beings to drive the plot, back to classics such as Misery -- whose depraved protagonist would share some psychopathic qualities with Mr. Mercedes -- or Cujo, which gave us the willies with a simple story about a dog that got rabies.
Nor is Hodges King's usual hero. He's about 25 years older than the typical liberal white guy King stand-in of most of Big Steve's work, and for once the story is not set in Maine -- it's in a dumpy Midwestern city with a lousy economy, which one baseball-related reference suggests may be Toledo.
King still has trouble writing from inside the heads of women and black people, though he's getting slightly less cringeworthy as he ages.
Mr. Mercedes joins that enormous body of popular culture in which books would end in the second chapter and movies would be over in the first 15 minutes if someone with a shred of common sense would only call the police.
It's is a gripping story set in a familiar real world that will have you on edge from the very first page.
But, please, keep in mind that it's just a story.
Free Press education reporter Nick Martin, a longtime Stephen King fan, still thinks Salem's Lot is the author's scariest book.