Some novelists write comedies of manners. Ruth Rendell wrote autopsies of manners. The 73 novels and short-story collections she published were chilly and unforgiving, written with the precision of a scalpel wielded by someone who waits until the blood has settled, the better to observe, probe, and describe the body laid before her with as little muss as possible. Rendell peeled back the layers and described exactly what she saw. Her method allowed no pretense of unfamiliarity, no false shock at whatever she found in her dissections, whether curiosities or diseases. But neither was there any nihilism.

It’s tempting to think of Rendell in relation to another English artist, the painter Francis Bacon, whose subjects often looked as if they had undergone an autopsy by hatchet. But whether screaming in horror or lying in ravaged repose, Bacon’s subjects mocked the impulse to turn art into statements of empathy. Pity and terror were beside the point, Bacon suggested, when suffering was the fact of existence. The quintessential Bacon image, capturing both his vision and his method, is Figure With Meat (1954), in which the screaming pope is less important than the hanging sides of beef framing him.

For all the cool control of her books, all of the refusal to be scandalized, Rendell could not, as Bacon did, accept the ugliness she saw. With her death last May at the age of 85, the contemporary English novel lost its finest and most stringent moralist. Not that there was anything prim or scolding in Rendell’s work. As a writer, she possessed a piercing knowledge of how the minor sins of pettiness, vanity, and hypocrisy often slide effortlessly into the commission of larger sins. Her severe contemplation of those sins, small and large, seemed that of an appalled humanist in an appalling age.

It’s why Rendell’s Inspector Reginald Wexford, over the course of 24 novels spanning the prime of his career to his retirement, never becomes a wise and charming codger. He is a man whose impatience is directly linked to his accumulation of experience, his conviction that humanity should be able to do better, despite all the evidence to the contrary. Wexford isn’t gruff or sarcastic in the manner of hardboiled heroes, nor is he an eccentric or a “character” in the manner common to the English detective novel and epitomized by the work of Agatha Christie, which Rendell loathed. Wexford doesn’t dispense warmth easily to strangers; instead, he acquits himself with polite formality on social and professional occasions. His inner monologue, though, is that of a man who has no impulse to shield himself from what he really thinks. He knows, for instance, that he loves his daughter Sheila, a successful actress, more than his other daughter Sylvia, whose slightly disheveled life irritates him, and who is aware of how her father judges her. The history of Wexford’s partnership with the detective working under him, Mike Burden, is one of withheld approbation slowly turning into professional respect and genuine friendship (just as Burden grows from a somewhat brash young man to a shrewd and seasoned veteran).

A police procedural is an accumulation of information that results in solving the case. In a Wexford procedural, the eventual resolution of whodunit offers little sense of closure. The narrative revelations typically lay bare transgressions that are more desperate than villainous, as well as psychic scuff marks and wounds that have already done lasting damage to both victim and culprit. And none of them, in Rendell’s pitiless view, excuses the crimes now on display.

The crime novelist Val McDermid makes a convincing case that the 24 Wexford novels—­the first, From Doon With Death, was published in 1964; the last, No Man’s Nightingale, in 2013—provide a survey of the changes in British society, as women and people of color join the workforce, as the populace becomes less Anglo, as issues like domestic violence cease to be solely regarded as private matters. They also embody, in the figure of Wexford, the unsteady balance of contemporary life: the belief that a person, by action and example, must stand against cruelty versus the simultaneous urge to take refuge. For Wexford, that refuge is his cherished wife, Dora.

This is clear in the closing paragraphs of No Man’s Nightingale, which are imbued with the sense of leave-taking—some of it relieved, some regretful. Wexford is toting up, ready to be done with those he found unpleasant, sad over the woman he will not see though he’d like to, wary of those he may encounter again, and—perhaps the hardest bit of honesty here—not ready to give in to the false hope that one of his own blood will be shielded from the unhappiness that awaits him. And, at the end, there is the refuge of Dora, “who stood on the other side,” in the home they have made, though there is no assurance that the thoughts that accompanied him will leave him at the threshold. It’s a passage of both engagement and retreat, and after nearly 50 years spent with this man, a far less comforting one than you might expect of an author taking her own leave of the character she has described as being less her alter ego than a portrait of herself.

The passage that best represents what is distinctive about Rendell’s fiction is the study of precarious balance in the opening paragraphs of the The Keys to the Street (1996):

The park is deserted by night. That is, the intention is that it should be deserted…. No vagrant could sleep undisturbed under the lee of the pavilions or the bandstand, but the police cannot search everywhere every night. The canal bank remains as a place of concealment amid the wide green spaces, and, in summer, the long grass under the trees.

What did we just read? The description of an enchanted refuge, or—because this park is inhabited by both the homeless and the killer impaling them on the park’s spiked fence—something more sinister? And why can’t it be both?

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In Rendell’s books, life is both sinister and ordinary. Rendell often turned to a quote from one of her favorite writers, Arnold Bennett, to describe her work: “Humanity treads ever on a thin crust over terrific abysses.” The ground is ready to give way in most of Rendell’s work. Her recognition of the thin, wavering line between the evil and the quotidian may explain the ease with which she stepped into the criminal mind. The contrast between the placid surface and the roiling substrata of derangement, a rebuke to the fetishized mastermind serial killers of contemporary popular imagination, is the very thing that makes her books so unnerving. And the ordinary characters in her novels, people as bound by their secrets as Marley’s ghost is by his chains, are no strangers to obsession, or to the way obsession can take over a life, as with the timid young woman who is the title character of The Bridesmaid (1989).

Some years ago, a friend told me, quite seriously, not to read The Bridesmaid in bed at night. Being a know-it-all, I didn’t listen, and found myself thoroughly terrified. Not even hearing my then-wife sleeping soundly beside me alleviated my fear. About a year later, a friend to whom I had given the book called me on a Saturday afternoon in early summer. She was on vacation in Los Angeles. It was a beautiful day, and she had promised her host she’d join her for a walk as soon as she finished reading The Bridesmaid. But now she was calling to tell me that, in spite of the warmth and sunshine, she was completely spooked. We had both fallen prey to Rendell’s mastery of the tires-on-ice moment: when a novel’s intersecting elements begin their inexorable slide into calamity.

The non-Wexford novels, the stand-alones, are black comedies about the public consequences of private deceptions caused by the crossed wires and mixed signals that connect characters to each other. None are more mismatched than the victims and killer in A Judgement in Stone (1977), which begins with the sentence: “Eunice Parchman killed the Coverdale family because she could not read or write.” Val McDermid has pointed out that the sentence is a riposte to those who believe all crime fiction is formulaic, revealing in the first sentence the identity of the killer, the victims, and the motive. A Judgement in Stone is about an illiterate housekeeper whose secret is found out by the bourgeois family she works for. Their efforts to educate her, their assurances she needn’t be ashamed, only make her feel more of an outsider, more of a freak in their world, which takes literacy for granted. The novel is a cunning and malevolent prank played upon the reader. We go along, enjoying Rendell’s wit, the ingenious plotting, the swift delineation of character—and suddenly we realize that the thing allowing us to take such pleasure, our literacy, is the very thing that gets the family in the novel killed. (The book was the inspiration for Claude Chabrol’s film La Cérémonie.)

Rendell’s is a sensibility that encompasses both the Gothic and the sick joke. The morbid romanticism that defines the climax of The Bridesmaid (which Chabrol filmed) would have made Emily Brontë laugh in sheer admiration. And the rapturousness of the novels that Rendell wrote under the pseudonym Barbara Vine, with King Solomon’s Carpet (a love letter to London written in arsenic and laudanum) and No Night Is Too Long (which may be the closest thing we have to a gay Wuthering Heights) counting among the best of them, have the ominous, night-blooming strangeness of 19th-century Gothic novels.

There is, as in many Gothic novels, an old house at the center of Dark Corners, Rendell’s last novel. The protagonist, Carl Martin, is a blocked novelist who inherits a house from his father in a rapidly gentrifying London neighborhood. Deciding that renting out some of the rooms will earn him the income he needs while he wrestles with his second novel, Carl impetuously takes a creep named Dermot McKinnon as his tenant. Dermot gets hold of some incriminating information about his new landlord. Carl, morally though not legally guilty and too frightened to go to the police, accedes to Dermot’s blackmail, letting him live in the rooms rent-free as Dermot gradually takes over more and more of the house.

The coldness that alienates some readers from Rendell is also what makes those of us who enjoy her indulge in grim laughter at the plight of her characters. The only assurance that Rendell offers her readers is that no matter how uncomfortable a situation her protagonists find themselves in, it will always get worse. When circumstances remove Dermot from the picture and Carl at last feels free, Dermot’s dim girlfriend Sybil simply takes over the blackmail scheme and becomes Carl’s new unwanted tenant. It’s the blitheness of the perfidy here, the ease with which Dermot and Sybil slip into criminality, that Rendell holds up to cool assessment. At the same time, it’s Carl’s pampered nature, his shock that there is such deviousness in the world, that makes him such a patsy.

The novel’s secondary characters have the particular Rendell characteristic of being both odd and ordinary at the same time. There’s a freeloading woman who moves into a dead friend’s apartment, taking over the place, wearing the friend’s stylish clothes as though it were all her due; an older man who finds that his only pleasure in retirement is taking bus trips to sections of London and the surrounding country he has never visited—not to actually get off the bus, just to take the rides. These two characters are not gracefully integrated into the novel; they’re slivers of Rendell’s sensibility but not fully working parts of her schematics. The book doesn’t stand with the horror of The Bridesmaid or A Judgement in Stone, or the strange dark-hued enchantment of The Keys to the Street, or the sick-joke whammy of A Sight for Sore Eyes. But it’s hardly a falling off. There never was a falling off in Rendell’s work, which instead displays a growing acuity of psychological perception and authority to her moral vision. Rendell’s work habits were reliable: She produced a novel a year, sometimes more. The weight of her achievement lies less in individual volumes than in the body of her work, just as the pleasure of reading it comes from encountering that deepening sensibility in book after book.

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Those who have never read a book by Rendell should feel free to start anywhere. Her detective series needn’t be read in order. Mary McCarthy, in the particular way she had of blending praise and derision, once wrote of the novels of Ivy Compton-Burnett: “A Compton-­Burnett is a reliable make, as typical of British Isles workmanship as a tweed or a Tiptree or an Agatha Christie.” (Wexford relaxes with a Compton-Burnett in the final scene of The Monster in the Box.) We are used to critics writing this way of popular novelists, but not of the ones who have been deemed literary. Rendell was both, and one of the major English novelists of the last half of the 20th century. In her essay on Compton-Burnett, McCarthy goes on to say something that neatly disposes of the tendency to look down on writers simply because they work in a particular genre. “Detection,” she writes, “seems to be natural to the English novel; this is true even in Jane Austen where a Wickham or a Frank Churchill is ‘found out.’ The traditional English novel, from Fielding on, deals in lost-and-found identities, concealment and discovery. Unlike the continental novel (or the American), it is a kind of commodity with a warranty of unfailing reader-interest contained in the plot, which works like a factory mechanism—the mills of the gods.”

It may be odd to talk about a writer who identified herself as a liberal (made Baroness Rendell of Babergh in 1997, she sat for Labour in the House of Lords) as a traditionalist, but in some essential way Rendell was one. Of all the changes in society that her books recorded, it was women coming to have more freedom and self-definition that pleased her the most. Some of the most withering passages in Dark Corners link the old-school view of women as housekeepers and mothers to the tea-cozy insularity of English provincialism, and find the dank odor of a Sunday dinner’s boiled vegetables rising from both. But the changing makeup of the English populace and the ability of formerly marginalized people to have more of a say in their lives did not, for Rendell, much change morality.

Over the last few years, the thoroughly overexposed critic Slavoj Zizek has said that liberals are particularly ill equipped to stand up for liberalism. Whatever he was thinking of, Rendell stands as a magnificent exception. She remains a particular delight for readers who don’t seek false comfort, who don’t confuse compassion with sappiness, who don’t believe good intentions are more important than results, who don’t believe people are ever fully free of vanity, and who so often find human beings appalling because, to the writer, the work of being a decent human being is sacred. That Rendell sustained this vision while writing superbly in several genres—the detective story, the Gothic novel, the black comedy of manners—­is another sign of her commitment to tradition. Rarely does a novelist express an ever-deepening but consistent psychological and moral vision over so many years. Rarely does a vision that could feel so grim in what it apprehended seem such a sign of the persistence of hard-headed decency.