Stephen King is one of the few writers so well known that even people who don't read have heard of him. As a result, he is judged by different rules.

When evaluating a new King, you have to come at it from at least two angles. The first and most important is simply whether it's a good book. There are no free passes, even after decades of super-bestsellerdom. Next, there's the question of whether it's a good Stephen King book, because he puts each novel in front of bazillions of readers who return for his distinctively unstoppable storytelling engine, his particular and hugely dependable voice. Their expectations can be a mixed blessing, and there have been very good King novels (The Tommyknockers springs to mind) whose initial reception was muted because he dared to step outside his normal range.

The Tommyknockers was published a long time ago, however, and after the Dark Tower fantasy series and non‑fiction such as the magisterial On Writing, King isn't as trapped in the horror ghetto as he once was. Therefore, there is a third level of potential scrutiny – that of assessing the book within whichever genre it inhabits. From the shoutout to James M Cain on the dedication page to the George Pelecanos quote on the back, it is clear that Mr Mercedes is firmly positioned in suspense-thriller territory and the non-supernatural world – somewhere King evidently feels increasingly at home.

While horror novels are about an idea, crime and mystery books tend to stand or fall on plot. Ardent fans aren't going to check what the story is about, however, before deciding whether to purchase: if you've been waiting impatiently for the new King then you're going to buy the thing even if it's about a pebble called Deirdre living out her retirement on Mars. For the record, Mr Mercedes concerns overweight former homicide detective Bill Hodges, who is lonely, retired and bored to the point of being vaguely suicidal, whiling away his days watching bad TV and playing thoughtfully with his father's gun. Thankfully, Brady Hartfield, the unhinged killer behind a celebrated local atrocity – one of the unsolved cases that bugs Hodges in the long watches of the night – has the ex-cop in his sights and is determined to needle him into ending it all.

Hodges takes the bait and slowly starts to turn the tables, with the aid of new friends and even a lover picked up along the way. At its heart, Mr Mercedes is a traditional cat-and-mouse story about a psychopathic killer and the renegade cop who makes it his mission to bring him down, with parallel intertwined narratives charting the detective's rebirth and exploring the killer's psyche. It is tight, focused and manages to avoid the excessive use of extraneous characters and prose folksiness that are the Big Man's only occasional faults.

It is also rather gentle, by the standards of this genre, at least before King puts the pedal to the floor and drives headlong toward the climax – during which it becomes clear that all bets are off. When it comes to grabbing an audience by the throat and giving them no choice but to keep reading, King has no equal, and I challenge you not to finish this novel in one breathless sitting.

Good book? Hell, yes. Good Stephen King book? Absolutely.

When judging it purely as a thriller, that will depend on taste. The truth is that King transcends genre, and is too warm and compassionate a writer to settle for jaggedly noir suspense, or to write some cold shard of a novel populated by modishly nihilistic ciphers. He is not in business merely to show you how venal humankind can be – though he'll open that door and make sure you get a good look. Notwithstanding his reputation as the Master of the Dark Side, King is always far more interested in how we get by in life, how we manage to care for one another and walk together toward the light, despite the darkness lurking within us all.

• Michael Marshall Smith's latest novel (writing as Michael Marshall) is We Are Here (Orion). To order Mr Mercedes for £16 with free UK p&p call Guardian book service on 0330 333 6846 or go to guardianbookshop.co.uk.