It takes one to know one.

That playground taunt is, like so many cliches, grounded in truth. It really does take one to know one, which goes a long way toward explaining the perversely effective law enforcement personnel in the novels of Mo Hayder, the British author whose works now regularly appear in hardcover in the United States as well. Her novels cast spells as no other novels quite do.

They detail the darkest, coldest, most forbidding aspects of human nature — aspects that are spread democratically among the heroes and the villains. Yet despite the gory premises that ignite these books — most often, the luridly detailed adventures of serial killers and creative sociopaths — Hayder's novels oddly are not depressing.

Instead, they leave you in awe of her courage. It's as if she has willed herself to stay awake all night long while everybody else sleeps, keeping her eyes open and her reflexes sharp in order to witness the worst of what our fellow creatures might do. She doesn't relax — hence the rest of us can.

Law enforcement authorities perform the same vital function. They do, in real life, what Hayder does in stories: Rope off the nasty parts. Keep them visible as cautionary tales, but far enough away from us so that they pose no real danger.

What, though, is the cost of this service for the cops in a Hayder novel?

That's the question that haunts her work. If it takes one to know one, then how do her characters — so severely damaged themselves, so flayed by nightmares and incessantly hassled by ghosts — keep their private demons at bay long enough to go after the public ones, the ones that otherwise might threaten the innocent?

Hayder, whose new novel "Hanging Hill" (Atlantic Monthly Press) continues her astonishing string of brilliant, hypnotically readable mysteries, is part of a golden era of literary crime novels. She is among a clutch of writers who use crime and punishment the way Shakespeare used kings and wars: as the scaffolding from which to explore central questions about love, hate, guilt, ambition and fate.

To be sure, there have always been accomplished storytellers who eventually brought their gifts to bear upon the mystery genre, including Charles Dickens, Robertson Davies, Joyce Carol Oates and, most recently, John Banville, but those were — are, in the case of Oates and Banville — literary writers who turned to crime fiction as a secondary outlet for their talents. A fresh canvas.

What is distinctive about the present generation of top-tier mystery writers is that they started out in the genre. Their works represent not a shift, not an afternoon's dabble in a more popular form of entertainment than the average literary novel, but a commitment from the very beginning of a career to the mystery as the ideal arena for the most profound engagement with just what it means to be human.

Or, in the case of Hayder's villains, what it means to be inhuman.

This golden era, by the way, is an international phenomenon. Kate Atkinson, Fred Vargas, Ruth Rendell, Karin Fossum, Belinda Bauer, Declan Hughes, Louise Penny, Peter Temple: These writers — if you don't know their work, you ought to remedy that as soon as possible — hail from, respectively, Scotland, France, Great Britain, Norway, Wales, Ireland, Canada and Australia.

There are many others, too, of course, but those are the names that immediately spring to mind when I do a keyword search in my own mind for "crime" and "literature."

Hayder's "Hanging Hill" features an ending so shocking it may reverberate through you long after you've finished the book. It's not the standard conclusion to a well-plotted whodunit, the kind that makes you thump the side of your head and exclaim, "Oh, I should've figured that out!" Yes, the ending is a surprise — but it's the implication of that ending, spiraling off in horrific directions, that rocks you back in your seat.

In previous novels, Hayder has deployed characters such as Jack Caffrey, a police detective haunted by his brother's disappearance long ago; Flea Marley, a police diver with her own set of locked-and-loaded demons; and the Walking Man, a mysterious vagabond who moves in and out of Caffrey's line of sight, living on the ragged edge of civilization. Books such as "Birdman" (2000) and "Skin" (2009) crackle with Hayder's expert blend of social realism and atmospheric nuance.

Set in Bath, England, "Hanging Hill" introduces compelling new characters: Zoe Benedict, a tough-talking, motorcycle-riding cop whose past — and maybe her present — includes a perverse yen for maiming herself as a way of coping with stress, and her estranged sister Sally, a single mother desperately worried about money.

A terrible crime gets the action going. But what really distinguishes "Hanging Hill" are the complex relationships between Zoe and Sally; between Zoe and fellow cop — and boyfriend — Ben; between Sally and her creepy new employer, who clearly is up to no good.

Zoe, pushed to the brink by the case and by what she must do to ensure that a rough sort of justice will prevail, is appalled by what she sees in the mirror. "You're a monster," she tells herself. "You've become a monster."

Perhaps she has. But it takes one to capture one. Doesn't it?

JULIA KELLER is the Chicago Tribune's cultural critic. She won the 2005 Pulitzer Prize for feature writing.