“Father Brenner and I aren’t exactly on friendly terms. Maybe you could ask him.”

“It’s been what, maybe ten years now? He’s not one to hold a grudge. It’s not as if you broke that nun’s leg.”

After Mallory left the room, the other poker players fixed upon the face of the rabbi in dead silence. He cast his sweet smile on each player in turn, which was easy because he was holding the best cards of the evening. But he never said another word about Kathy Mallory and the nun, not even when they withheld his sandwiches and beer for a time. He would not talk.

Why do people like this character? I don’t know. If I had to guess, I’d say it harks back to old high school issues of making the cut, and this idea works well on both sides of the gender divide. Let’s say that it was possible for you to meet her on the street or in a bar. Would Mallory talk to you? Would you even register as a solid object, or would she look through you? These are trick questions and very Darwinian in the sense of good survival instincts. Being ignored is actually your best possible outcome. If she’s interested, if she hurts you, then you’ve made the cut.

There are always questions about why she is the way she is. Well-intentioned (albeit delusional) fans long to pin down the exact moment in time when her mind went awry-so they can tweak her and fix her and ruin my career. More rational readers want me to do the mending. The nicest people ask (beg) for a kinder, gentler Mallory. I politely explain that if I give them what they ask for, I have no book. I’d like to say, “This is crime genre and not a damn soap opera.” (In person, I am polite. On the page-not so much.) Each novel was written to stand alone, and reading one out of order will in no way ruin the plot of any other book in the Mallory series-so you won’t be charting warm and fuzzy life-affirming changes in the character. However, gaining personal insight here and there creates the illusion of growth in a sociopath who cannot change what she is.

She has a partner named Riker, who keeps a very special rainy-day bullet in the nightstand by his bed, and he sometimes thinks of loading it into his gun. But he never speaks of this. There are no overt signs of his state of mind. And Mallory should be the last person on earth to intuit his suicidal ideation. And yet, there are nights when she parks her car in front of his apartment building and looks up toward the bathroom window and the glow of Riker’s plastic Jesus nightlight. When every light but this one has gone out, she drives away.

Perhaps her only clue to Riker’s sadness is in the chaos that he calls home. It’s best described by a character who once said to him, “You know why you don’t have cockroaches? Those genius bugs-they know it’s not safe to eat here.” Mallory, that neat freak who straightens pictures on other people’s walls, once broke into Riker’s apartment and cleaned it for him. She dragged her mop and bucket from room to room, stopping on the threshold of the bathroom, where exquisite good taste kicked in, and she wanted to trash that plastic Jesus nightlight. Instead she cleaned it and left it shining so that Riker would not stumble and fall in the dark.

So what’s in a name when it comes to dangerous pathology?

The pigeonholes that we make for people like Mallory are only for convenience’s sake. We are all special cases. I am sometimes asked, “How does a sociopath differ from a psychopath?” (Here you have to bear in mind that we live in an era of broadcast news that uses authors of techno-thrillers as weaponry experts to explain what’s going on in an actual war. And they have other fiction writers on standby if there’s a plague coming.) So I respond to the question from my audience. (What the hell. I can’t do worse than the amateur expert who sent America to the hardware store one day with the promise that duct tape would protect us from nuclear radiation.) I usually preface my remarks by warning people that the quacks on their favorite television shows cannot agree on this point of mental aberration. However, real doctors seem to have a consensus in their professional journals, which, alas, lack the credibility of the bestseller list.

It appears that there is no longer any distinction made between a sociopath and a psychopath. Based on research, I can tell you that those terms are used interchangeably in academic literature. And a quote from one psychologist of my acquaintance sums up modern policy on this matter: “Today’s sociopath is yesterday’s psychopath.” Putting rational thought to one side for the moment, common usage of these particular words carries more weight with the general public: Many people, with and without television credentials, see a sociopath as someone who can shoot a baby in the head and sleep through the night, and a psychopath as someone who can eat the face off a baby and sleep through the night.

Go with whatever definition makes you the most uncomfortable.

For some readers, Mallory is entirely too real. But I find that letters from mental patients are frequently the most insightful, and I welcome them. In my view, madness is a place. You go. You come back. And I think we all take turns being the mental patient. Without a touch of crazy, literature can be a desolate place. In the current climate of careful speech, even fearful speech, smoke-free film scripts, thought-free songs, and child-proof locks on American minds, the oft-repeated lament of the arts is “Where have all those wonderful madmen gone?”

The strong (and defective) character of Mallory may be what people remember best about these books. However, in a book where character is everything, you have nothing but an essay with no legs. The plot is the animation that runs you at gunpoint from cover to cover, sometimes at a heart-attack pace, a race to the end; and sometimes the plot is crawling, dragging its nails in the dark, coming up behind you… and then… at the end, you should be startled, and your next reaction should be “Oh, of course.”

Most important, the plot has to work with the protagonist. You will sometimes hear the literati say that they have no control over their characters, and they frequently alter a book because their protagonist would never do a thing like that. This should not happen in the crime genre, where there are promises to keep. The author must be in control of the material; this is the appeal, the draw, and the covenant with the reader. You should not be subjected to a thousand pages of angst, boring descriptions of the wallpaper, and the added misery of watching the protagonist boil eggs for breakfast. Instead, you are entitled to a sleek plot that will carry you somewhere, a plot with fangs and moving parts, a beginning, a middle, and a solid resolution.

I promise to tell you a story.

Ideally, the setting of every story should be a place that you can inhabit for the duration of a novel, and Manhattan, which figures prominently in most of my books, takes on character status. So this is not the dreaded scenery description; it’s character development, and I always aim to make it painless:

Riker’s binoculars strayed to the surrounding buildings and then down below to the stream of late traffic. Ah, New York, all decked out in city lights like sequins on her best dress-all dazzle and smart moves. He had seen the city in harsher light, and he knew she was really a whore, but that could be fun, too.

Stone Angel was a departure, a foray into southern gothic and a different kind of setting, a place where nature is no small player and every living thing is running for its life or running for its supper:

One osprey flopped its catch onto the grass. The fish struggled under the bird’s talons; its silver scales were striped with watery blood. The fish hawk was so intent on tearing flesh from bone, he paid the woman no mind as she drew closer, smiling benignly on the creature and his bloody living meal, nodding her approval of a good catch.