One thing made a difference: The actions of Lucie’s father, Tim Blackman, who arrived in Tokyo to join his other daughter, Sophie, in publicizing the search and prodding the police. Richard Lloyd Parry, Tokyo bureau chief for the Times of London, covered the case as it unfolded, first over the course of several months while Lucie’s whereabouts and abductor remained unknown, and finally for the six years it took to try the man accused of killing her, Joji Obara. The book Parry wrote about the case, “People Who Eat Darkness,” is an exceptionally perceptive and nuanced look at a terrible crime, one that put nations, institutions and family members at odds, and often into bitter and toxic conflict.

Unlike Truman Capote, author of “In Cold Blood,” the most celebrated true crime narrative of all, Parry is in essence a reporter; this is no “nonfiction novel.” But like Capote, he’s less interested in dishing the eerie or lurid details than he is in exploring the penumbra of the crime, the complex factors that fed into it and the unpredictable effects it had on an ever-spreading network of people. The true crime genre has a (mostly well-earned) reputation for trashiness, but it fascinates for legitimate reasons, as well. Transgression, justice and punishment speak to the very heart of what a society is, how it holds its people together and how they decide who lies beyond the pale.

Because Lucie Blackman was a foreigner, and one employed in an industry that the Japanese view as disreputable, the Tokyo police were inclined to dismiss her disappearance. Bar hostesses get paid to talk to and flirt with customers, and they are expected to go on (paid) dinner dates with them outside the clubs where they work, but it’s an arrangement that usually stops short of actual sex. Nevertheless, the Japanese think of most foreign hostesses as irresponsible, drug-loving backpackers who might well run off without telling anyone or get mixed up with dangerous people. Whether or not a Westerner would call what bar hostesses do a part of the sex industry, for the Japanese, these women belong to that category of “bad” girl who can expect little help or concern from authorities should she get into serious trouble.

Crime is not what it was in Capote’s day. In addition to finding and building a case against the perpetrator — jobs for law enforcement authorities — there’s handling the media, a task usually left to the victim and his or her relatives. Lucie’s father proved, initially at least, to be a master at this. Tim could detach himself emotionally from the horror of his situation and strategize. He was able to capitalize on a G-8 summit meeting being held in Japan around the same time Lucie vanished and parlay it into the intervention of British Prime Minister Tony Blair. Blair publicly asked Japan’s prime minister to front-burner the investigation, and met with Tim and his younger daughter Sophie while he was in Tokyo.

The police, who had been dragging their heels on Lucie’s disappearance, found this development (which made perfect sense in the political context of Britain) flabbergasting. Still, it worked: Lucie, who might have been written off as one of those “disposable” women of dubious virtue, was conclusively cast as an innocent girl, “naive perhaps, out of her depth,” but an adventurous daughter rather than a reckless slut. Tim was driving the narrative, as an electoral campaign manager might put it, and he was good at it. He liked talking to the press, even the tabloid press, and they liked him.

But if Tim was good at telling Lucie’s story, he was less successful at telling his own. Some of the most penetrating passages in “People Who Eat Darkness” concern what Parry refers to as the “script” expected from bereaved parents. Years later, Parry covered a press conference given by the father of another murdered girl and recognized in him “everything the world expected of a man in his situation: broken, helpless, turned inside out by loss.”

Tim, however, was composed, which aroused a formless popular suspicion regarding his sincerity. In similar cases, this uneasiness frequently takes the form of outside observers suddenly deciding that the parents might be implicated in their child’s disappearance or death. Tim, halfway around the world when Lucie vanished, was immune to that, but when he quarreled with the rich businessman funding the private search for his daughter, accusations of self-interest and even exploitation surfaced.

Lucie’s mother, Jane, on the other hand, behaved exactly as a grief-stricken mother is supposed to. In some respects, the truth about her parents’ failed marriage is as unknowable as the events of Lucie’s final hours. Unamicably divorced, Tim and Jane avoided even being in the same room together throughout the crisis. Was Jane, who seems to fall for every kind of supernatural hokum that crosses her path, pathologically vindictive, or was Tim as big a shit as she claimed? Just when you think you’ve made up your mind on that question, a new development comes along to knock you into the other camp.

As for the perpetrator himself, he remains something of a cipher to Parry, who was never able to interview him. Obsessively camera shy, Obara deftly avoided being properly photographed even after his arrest. He was clearly demented, as a long, self-justifying self-published book (disguised as the work of concerned supporters) amply demonstrates. Resolutely confident and unrepentant, Obara was also utterly unlike the vast majority of Japanese criminal defendants. (Parry explains that the justice system there depends almost completely on the ability of police investigators to shame suspects into confessing.) They simply didn’t know what to do with him. The Japanese blamed Obara’s recalcitrant behavior on his Korean ethnicity.

The Blackmans and Obara, Western-style players, descended on a criminal justice system unprepared to cope with them. “The inadequacy of its police force is one of the mysterious taboos of Japanese society,” Parry writes, “a subject that the media and politicians strain to avoid confronting, or even acknowledging.” The blunders of the police were many, but they could also be dogged investigators. Their real problem, according to Parry, is that they are good at dealing with “conventional Japanese criminals,” but when faced with the unexpected, they’re “sclerotic, unimaginative, prejudiced and procedure-bound.”

Obara behaved like a British or American criminal — taking charge of his defense, actively contesting the prosecutors, formulating a counternarrative to account for Lucie’s death. Watching how Japanese institutions responded to him, as well as to the Blackmans’ efforts to influence the investigation, proves fascinating. Since true crime, at its best, serves as a window on what a society cares about — how it constitutes not only what’s right and wrong but what’s sympathetic, reasonable, acceptable and important — the Obara trial was a most illuminating culture clash.

Parry doesn’t, however, forget what lies at the root of this drama: the death of a young woman who, whatever her doubts or flaws, had every reason to hope for a wonderful life. As the investigation would eventually reveal, this tragedy was eminently preventable. The people who tried to tip off the police about Obara were dismissed as not worth listening to. Let’s hope they’re not the only ones to learn from that mistake.

A far more unsettling finding is buried in this otherwise up-with-reading news item. The Ohio State researchers gave 70 heterosexual male readers stories about a college student much like themselves. In one version, the character was straight. In another, the character is described as gay early in the story. In a third version the character is gay, but this isn’t revealed until near the end. In each case, the readers’ “experience-taking” — the name these researchers have given to the act of immersing oneself in the perspective, thoughts and emotions of a story’s protagonist — was measured.

The straight readers were far more likely to take on the experience of the main character if they weren’t told until late in the story that he was different from themselves. This, too, is not so surprising. Human beings are notorious for extending more of their sympathy to people they perceive as being of their own kind. But the researchers also found that readers of the “gay-late” story showed “significantly more favorable attitudes toward homosexuals” than the other two groups of readers, and that they were less likely to attribute stereotypically gay traits, such as effeminacy, to the main character. The “gay-late” story actually reduced their biases (conscious or not) against gays, and made them more empathetic. Similar results were found when white readers were given stories about black characters to read.

What can we do with this information? If we subscribe to the idea that literature ought to improve people’s characters — and that’s the sentiment that seems to be lurking behind the study itself — then perhaps authors and publishers should be encouraged to conceal a main character’s race or sexual orientation from readers until they become invested in him or her. Who knows how much J.K. Rowling’s revelation that Albus Dumbledore is gay, announced after the publication of the final Harry Potter book, has helped to combat homophobia? (Although I confess that I find it hard to believe there were that many homophobic Potter fans in the first place.)

Absurd as this tactic may sound, many publishers are already kind of doing it — and catching hell. Although the term “whitewashing” is most often used to describe film and TV adaptations in which white actors are cast as characters who were people of color in the original book, something similar also happens with book graphics. Novels about black or Asian characters have been given cover art that features white people.

Controversies over cover-art whitewashing, and other attempts by agents, editors and publishers to downplay or even eliminate minority characters, have roiled the world of young adult literature in recent years. The author Justine Larbalestier (who is white) wrote a YA novel, “Liar,” with a black heroine in 2009, but her publisher insisted on using a photograph of a white teenager for the cover. Larbalestier took their disagreement public and the ensuing scandal persuaded the publisher to back down. Ursula K. Le Guin, a revered science-fiction and fantasy author who has often chosen dark-skinned people as her protagonists, has had to put up with seeing them depicted as white in cover art and film adaptations for decades.

Publishers argue that they’re only trying to make sure their authors’ books find the widest possible audience. What they mean is that a certain percentage of white (or straight) readers will summarily conclude a book isn’t for them if the face on the cover fails to resemble their own. Sad to say, the publishers are probably right about that. While the readers in the Ohio State study didn’t get to choose the stories they read, many of them were deciding how much to invest in the protagonist and his experiences — how much to identify — on the basis of his sexual orientation or race.

Authors, fans and observers are rightly disgusted by the practice of cover-art whitewashing. It shouldn’t have to be that way. But some commentators on the controversy seem to think that if publishers act as if race or gender or sexual orientation isn’t a factor in what many people decide to read, somehow it will simply stop being a factor. This seems unlikely. If it were so easy to rid people of their prejudices, the world would already be a much pleasanter place. It takes regular exposure to different types of people in the course of everyday life — at school and in the military, the workplace and the neighborhood — plus a whole lot of time and peer pressure to wear bias down.

Well, it takes that — and maybe the magic of storytelling? The readers in the Ohio State study did become more understanding of gay and black people after they were (let’s not put too fine a point on it) tricked into identifying with them. This type of sleight-of-hand is something only a non-visual medium like prose fiction can pull off. It can firmly lodge readers inside an imaginary person’s head without ever showing them his or her face. In Neil Gaiman’s “Anansi Boys,” for example, the narrator never explains that all the principle characters are black, and each reader will come to that realization at a different stage in the narrative. It’s Gaiman’s way of tweaking the very common readerly assumption that defaults all major characters to white unless their race is otherwise specified. (And sometimes not even then, as quite a few young fans of “The Hunger Games” demonstrated by being astonished when a supporting character, clearly described as black in the novel, was played by a black actress in the film.)

Of course, not all readers are white or straight, and the ones who aren’t deeply appreciate novels that advertise the diversity of their characters. It’s about time they got heroes and heroines who looked like them, and novels that speak to their distinctive experiences. They have been identifying with characters across the boundaries of race, gender and sexual orientation from time immemorial, and are masters of the art, but understandably they’d like to give their ninja skills a rest. Furthermore, there are also white readers who prefer variety in their fiction or are deliberately trying to correct the imbalances of the past.

Nevertheless, if you believe, as many Americans have since the days of the Puritans, that books ought to morally improve their readers, then maybe there’s a place for a little judicious whitewashing in the writing and publication of fiction. It has literally been demonstrated to change hearts and minds, at least for a while. That’s more than many consciousness-raising efforts — including righteous lectures delivered by the enlightened — can say.

Further reading

Ohio State University’s research blog on the study of the experience-taking while reading stories

The Booksmugglers blog on notable recent instances of book-cover whitewashing in YA.

Ursula K. Le Guin writes for Slate about the changes made to the race of major characters in the TV adaptation of her “Earthsea Trilogy.”

Hunger Games Tweets, a Tumblr compiling and discussing the response of some fans to the casting of a black actress as a supporting character in the film version of Suzanne Collins’ novel.

The Aleppo Codex is the most authoritative version of the Hebrew Bible, produced in the 10th century by the great rabbi Aaron Ben-Asher and the scribe Shlomo ben Buya. Friedman, who lives in Israel and has covered the Mideast and the Caucasus for the Associated Press and other publications, explains that the codex’s significance to Jewish faith and identity is more than symbolic. As a people scattered across the globe, “instead of being bound by a king, a temple, or geography, [Jews] needed to be bound by something else, something portable. What emerged was the idea that a people could be held together by words.” Yet in the centuries before printing, when words were transmitted orally and by copyists, it was all too easy for mistakes and variations to creep in, and “Jews could not be held together by a book if they were not reading precisely the same one.”

The codex was the perfect version of the Bible, a sort of atomic clock of Judaism, and intended to be the model for all subsequent copies. Its early history was fraught: captured by Crusaders in the fall of Jerusalem, ransomed by the Jewish community in Cairo and consulted by the fabled sage Maimonides, it was eventually taken to the Syrian city of Aleppo. There, it resided for half a century. Although it was well-cared-for by Aleppo’s Jewish community, it had come to be revered as a relic or treasure; few were allowed to see it and no one was allowed to copy it.

All that changed in 1947, when the establishment of the state of Israel by a United Nations resolution led to unrest in the Arab world and the harassment and persecution of Jewish communities in Muslim nations. In Aleppo, this took the form of riots and the sacking of the synagogue. The codex — commonly referred to as the Crown — was supposed to have been consumed in a fire set by the mob.

It was not, and in 1958, the Crown was smuggled into Jerusalem by a cheese merchant who was one of the few Syrian Jews to receive official permission to emigrate to Israel. Friedman became interested in this “lonely treasure and millennium-old traveler” in 2008, when he decided to write an article about it. He imagined the piece would be “an uplifting and uncomplicated account of the rescue of a cultural artifact,” but what he discovered instead was a thicket of conflicting reports, missing records, puzzling omissions, stonewalling officials and obsessed amateur sleuths.

The mysteries surround not the ancient history of the book, but what happened to it between 1947 and the mid-1970s, although even establishing where things got dodgy proved to be a challenge. Friedman relates each piece of the story as he untangled it himself, and part of the pleasure of “The Aleppo Codex” is getting to tag along on the heels of a real-life investigative journalist as he does his detective work. Those years spent writing wire copy have not eroded the author’s eloquence, either, as the book’s headier touches attest: “Down in those streets, the stores now shuttered, the women of the manzul were receiving clients, and the men were submerged in cafe smoke like deep-sea divers, tubes between their lips, inhaling the rose-scented oxygen of water pipes.”

While the official story simply states that the Crown was presented to the president of Israel, Itzhak Ben-Zvi, upon its arrival in Jerusalem in 1958, Friedman unearthed evidence that this was no simple handoff. Most of the Jewish community of Aleppo had immigrated to Israel, and their rabbis insisted that the Crown was supposed to have been delivered to them. The cheese merchant maintained that the rabbis still living in Aleppo, the ones who had passed him the book, told him no more than to give it to “a religious man.” (The Syrian government prevented communication with the Jews in Aleppo, so his story could not be confirmed or disproved.) The Aleppo rabbis decided to take their complaint to court.

This dispute embodied major tensions within the newly formed state. The Aleppo rabbis had presided over what was, as Friedman writes, “an old community by the time Roman legions destroyed the Jewish temple in Jerusalem in AD 70.” The Israeli leadership, “largely secular European socialists,” did not strike the Aleppo Jews as “representing the entire Jewish people.” Why should these interlopers be allowed to appropriate a book that had been the focal point of Aleppo’s venerable Jewish community for half a millennium?

The codex lawsuit was also a dramatic example of what Friedman describes as a “largely untold story” concerning the migration of the Jewish Diaspora to Israel after the formation of the state. Along with the movement of people, there was also a “great migration of books.” Jews from all over the Muslim world were forced to leave neighborhoods their families had inhabited for centuries. Not only did distinctive local cultures vanish overnight, but so did many of their treasured texts, left at docks and airstrips with the promise that they would be forwarded on to their owners in Israel, and then never seen again. Well, not exactly never: Some of these books and scrolls turned up later in state archives and even in booksellers’ shops.

If that were all there was to the story of the Aleppo Codex, it would be fascinating (and dismaying) enough, but after wrestling with the shadowy story of how the Crown got to Jerusalem, Friedman turns to a second and even more disturbing question: Where is the rest of it? About 200 pages, some 40 percent of the Crown, are missing. These are the most important parts of all: the first five books of the Bible, also known as the Pentateuch and the Torah. Again, the official story holds that portions of the Crown were burned in the 1947 fire, but this has since been disproved. A couple of single pages have been found in places as far-flung as Brooklyn, N.Y., where they were carried around by Aleppo old-timers as good-luck charms. The bulk of the Torah, however, remains MIA.

This is where Friedman’s investigation gets especially lively, as he consults with a former Mossad case officer and secretly records an impromptu interview with one of the dozen or so men rich enough to have bought the missing pages. Supposedly, this collector and his daughter were approached by two dealers with a briefcase at a Jerusalem book fair in the 1980s. They were shown an old codex identified as part of the Crown, but the collector says he refused to buy it because the price was too high. One of the dealers later turned up dead in a Tel Aviv hotel room registered to a man who didn’t exist.

Friedman has his suspicions about the collector’s story: Would this man really consider $1 million too much to pay for a supposedly priceless text? He devotes most of his energy, however, to getting to the bottom of who is responsible for ripping out the heart of the Crown and selling it on the black market. As he settles on three likely culprits, “The Aleppo Codex” builds to a moral crescendo more impressive than the climactic fight scene in any thriller. “A volume that survived one thousand years of turbulent history was betrayed in our times by the people charged with guarding it,” Friedman writes. “We might file this tale between Cain and Abel and the golden calf, parables about the many ways we fail.”

As with “Wolf Hall,” the central character in “Bring Up the Bodies” is Thomas Cromwell, master secretary to King Henry VIII of England. The son of a drunken, abusive blacksmith, Cromwell has risen about as high as any commoner could hope to, entirely on the strength of his acumen, industry, cunning and resilience. As an often-quoted passage from “Wolf Hall” declares, “He is at home in courtroom and waterfront, bishop’s palace or inn yard. He can draft a contract, train a falcon, draw a map, stop a street fight, furnish a house and fix a jury.”

This is, incidentally, Cromwell’s own assessment, but he’s saved from vanity by the fact that his confidence is not just well-placed but precisely placed; he is the ultimate realist, and he possesses that most potent of assets, an excellent knowledge of himself. In the thousands of fictional retellings of Henry’s reign — most of them focused on his ambitious second wife, Anne Boleyn — Cromwell is typically depicted as a ruthless schemer. He got rid of Henry’s first wife, Catherine of Aragon, when Henry wanted Anne, and he got rid of Anne, too, when the time came. The first ejection led to the foundation of the Church of England and the second to the execution of six people.

As Mantel tells it — she describes the novel as “a proposal, an offer,” rather than an assertion of historical truth — Cromwell represents the vanguard of a new era, one in which ability trumps noble birth. He can countenance any number of insults from the arrogant aristocrats he works with because he knows that “chivalry’s day is over. One day soon moss will grow in the tilt yard. The days of the money lender have arrived, and the days of the swaggering privateer; banker sits down with banker, and the kings are their waiting boys.”

He would never dream of voicing such thoughts, of course, and part of the marvel of Cromwell the character is his self-control. “I never forget myself,” he tells the ambassador from the Holy Roman Empire at a moment when his temper has been sorely provoked. “What I do, I mean to do.” The style Mantel employs to write about this exemplar of the will is declarative to the point of bullishness; her voice is his. The character’s allure lies in his energy and his resilience, and it’s thrilling to hitch your readerly perspective to a man who can seemingly do anything and furthermore has the nerve to try.

But if Cromwell is a man of action, he’s also, at age 50, prone to reflection and haunted by the dead. “Bring Up the Bodies” opens with falconry in the picture-book English countryside during the king’s summer “progress” (a sort of nationwide tour) of 1535. Cromwell’s falcons are named after his two daughters, who, with his beloved wife, died in London’s intermittent epidemics. He hasn’t forgotten them, but it’s significant that he’s memorialized them as birds of prey. Above all, Cromwell nurses a grudge against all who participated in the downfall of his mentor, Cardinal Thomas Wolsey. Yet, he is not without warmth. A conscientious and covertly tender householder, he presides over the lives of assorted dependents from various social classes. His carefully concealed soft spot for distressed gentlewomen and exiled court figures like Catherine and her daughter, Mary Tudor, leads him to make small but largely unappreciated efforts on their behalf.

We are shown that Cromwell is ruthless — there’s passing mention of hangings in Ireland, among other things — but we also know that he is loyal. This is his saving virtue. His allegiance is to England and to Henry, who, like the late Cardinal, has recognized his worth and raised him up. Some of the more notorious highlights of Cromwell’s career — the dissolution and sacking of monasteries and other Church property and the execution of Thomas More, depicted in “Wolf Hall” — are cast in this light: England’s riches should belong to the state, not to Rome, and be utilized for the benefit of her king and people. Like a modern Labor Party politician, Cromwell tries to pass poor laws and work programs in the face of mighty resistance from Parliament and the aristocracy.

Throughout the first two parts of “Bring Up the Bodies,” this is the Cromwell we accompany. He is the king’s most valued councilor and is effectively running the country. His enemies are preening, scornful and often foolish noblemen, out to promote clannish interests or reconciliation with Rome. Anne Boleyn, his former ally, has turned on him, and turned off the king. “He has always rated Anne highly as a strategist,” Cromwell thinks. “He has never believed in her as a passionate, spontaneous woman. Everything she does is calculated, like everything he does,” yet she has overestimated her own security. They are two of a kind, perhaps, but unlike him, she has let her success go to her head and will, in consequence, lose both.

Discouraged by Anne’s inability to give him a son and harried by the vixenish ways that once enthralled him, Henry falls for Jane Seymour, “a plain young woman with a silvery pallor, a habit of silence and a trick of looking at men as if they represent an unpleasant surprise.” It becomes Cromwell’s job not only to clear the way for Jane to become Henry’s third wife, but to make the king feel that he is justified in discarding a second spouse. Cromwell pursues this goal in the conviction that sooner or later Anne would have come after him and his friends.

That’s the setup, but as the interrogation and trials of Anne and her alleged lovers commence, Mantel carries the reader into harrowing territory. Cromwell tricks a foppishly romantic musician into boasting of having slept with the queen (Mantel does not endorse the view that the man was tortured into this admission) and conducts a series of interviews with the four doomed noblemen accused of being her lovers and of plotting against the king. The four also happen to be Cromwell’s political enemies and, furthermore, key participants in a satirical court entertainment that depicted Cardinal Wolsey being dragged to hell by devils. “He needs guilty men,” Cromwell tells himself. “So he has found men who are guilty. Though perhaps not guilty as charged.”

Political horror is not a new literary mode — you can find it in the New Testament as well as in such 20th-century works as George Orwell’s “1984.” However, the protagonist in those stories is invariably the victim. “Bring Up the Bodies” devotes 270 pages to developing its hero, investing the reader in the superiority of his personality and cause, and then ushers him into the interrogator’s chair. Cromwell is contriving to send these people to the scaffold for crimes they quite possibly did not commit, however “guilty” they may be of others. Because he is our man ever bit as much as he is Henry’s man, we are, in some obscure way native to the laws of fiction, implicated. These are not easy chapters to read, although they are magnificently realized.

As assured as her implacable protagonist, Mantel walks the edge of a very sharp knife in the last part of “Bring Up the Bodies.” I don’t believe she cuts her feet on it, but sometimes it felt as if she were cutting mine. It’s impossible to repudiate Cromwell, but embracing him has become infinitely complicated. Of all the many fictional depictions of the moral quandaries involved in the exercise of great power, this may be one of the most disturbing. It comes much closer than any I’ve ever encountered to letting you know how it must feel to manage the fate of a nation: how intoxicating and how very, very perilous.

Hall, a creative-writing professor and crime novelist, teaches a course on “megabestsellers,” books that have sold in the “multiple millions” and that have gone on selling for decades after they were originally published. He considers a list of 12: “Gone With the Wind,” “Peyton Place,” “To Kill a Mockingbird,” “Valley of the Dolls,” “The Godfather,” “The Exorcist,” “Jaws,” “The Dead Zone,” “The Hunt for Red October,” “The Firm,” “The Bridges of Madison County” and “The Da Vinci Code.” Though the list seems fairly diverse, Hall insists that they all share 12 common elements — to such a degree, in fact, that they are all “permutations of one book, written again and again for each new generation of readers.”

This is sorta true and sorta not, depending on what your needs are. It is indeed a fact that bestsellers often feature “fractured families,” spiritual quests or doubts, “didactic” interludes that assure the reader he or she is learning something, “hot button” issues of the day and — in my favorite of Hall’s coinages — a theme he dubs “Bumpkins vs. Slickers.” But so do a lot of other books, from truly great novels to justly forgotten flops, American and otherwise. How helpful is it to point out “universal” traits of bestselling books if they turn out to be universal traits of most books? “Vanity Fair” is every bit as much a rags-to-riches story as “The Godfather,” and nostalgic yearning for a lost pastoral idyll has been a major literary motif since Virgil’s Eclogues.

Is it any surprise that popular characters ranging from Scarlett O’Hara to Michael Corleone tend to show “a high level of emotional intensity that results in gutsy and surprising deeds”? Or that readers prefer characters who “act decisively” rather than engaging in “navel gazing”? A successful plot, Hall explains, is one that quickly establishes a conflict or dilemma so that readers are “drawn forward by the momentum of the unfolding story as one complication after another challenges the central character and the original dramatic question mutates into another question and another.”

Well, of course it does. Yet, in Hall’s defense, I would point out that he is a creative writing teacher. For some reason, it is often the very people who say they want to write novels who seem to have the least understanding of what other people want to read. So Hall has no doubt seen countless examples of would-be authors — including people determined to work in commercial genres — who simply don’t grasp the most elementary principles of storytelling. While “Hit Lit” may seem, to many readers, like the literary equivalent of instructions on how to boil water, the sad truth is that plenty of those who speak contemptuously of Dan Brown’s prose are writers who could not get a child interested in a fairy tale.

True, I, too, would never call Brown a “good writer” — yet many very successful novelists are not: Stieg Larsson, for example. A book doesn’t have to be especially well-written, plausible or original to be a bestseller (although it can be). The characters don’t have to be particularly interesting, as John Grisham proves again and again. In fact, if there is one trait that all of the bestsellers Hall considers absolutely share, it’s that a lot of people like them.

That statement isn’t as inanely tautological as it may sound. As Hall points out, the common belief that publishers deploy splashy, expensive promotional campaigns to snow the public into buying millions of copies of terrible books is quite mistaken; publishers do not have that kind of power. Hall quotes the fabled editor Michael Korda on the subject (and Korda, having launched Jacqueline Susann and Harold Robbins, ought to know): “At least half the books on any given week’s bestseller list are there to the immense surprise and puzzlement of their publishers.” Publishers can provide a book with the ideal conditions in which to catch on, but only the genuine enthusiasm of the reading public will make it an ongoing hit. Word of mouth — one reader raving to another about how much he or she enjoyed it — is the single determining factor. And you can’t buy that.

So why does that public fall in love with some crappy books but not others? Hall makes one of his strongest points almost in passing: The bestsellers he considers are, he notes, “unique and creative mash-ups of traditional genres.” “Unique” may be stretching it, but most of them do combine familiar elements in less familiar ways — the recipe for successful genre fiction. “Gone With the Wind” transported the career-woman melodramas of its time into a historical romance. “The Godfather” is a family saga grafted onto a gangster story. The sensational historical-religious conspiracy theory at the center of “The Da Vinci Code” had already appeared in a nonfiction bestseller; Brown’s brainstorm was to change the delivery mechanism to a fast-paced thriller.

And more often than you might think, luck and timing play a deciding role. Anyone in the romance-publishing industry will tell you that the current racy bestseller, E.L. James’ “Fifty Shades of Grey,” is fairly typical of the low-profile genre called erotic romance. Thousands of titles with more or less the same characters and themes — many of them better-written and arguably more interesting than “Fifty Shades of Grey” — were on the market long before James came along. But James emerged from the word-of-mouth factory that is Twilight fandom, and as a result her books introduced hundreds of thousands of readers to a genre they didn’t know existed, much as Stephenie Meyers had introduced them to the vampire romance novel a few years before.

Still, the essential quality separating most tentpole bestsellers from the rest of the genre pack remains an enigma. Why did “The Help,” among all the earnest, sentimental historical women’s fiction published in the past 20 years or so, sell 10 million copies? It’s easy, once the feat has been accomplished, to attribute a book’s success to this or that feature, but picking winners beforehand is another trick entirely. The one predictive factor that readers (and therefore publishers) consistently rely on is brand loyalty; an author who has done it once, they assume, is likely to do it again. That’s why the most consistent aspect of the bestseller lists is the reappearance of the same names, over and over.

Here’s something else you can count on: A person who can’t fathom why the public fell in love with Lisbeth Salander or Edward Cullen is probably not going to be able to write something they’ll like just as much. Whiling away a couple of summer afternoons reading a trashy novel is a harmless way of wasting time. But writing a book even you wouldn’t want to read? That’s just killing it.