What is it about Scandinavian mysteries that makes them, on average, so much better than anyone else’s? I’m not saying Americans can’t write good thrillers: Ross Macdonald’s Lew Archer series would come near the top of any aficionado’s list, as would Patricia Highsmith’s Ripley books. But these deeply psychological, highly individualistic portraits of twisted motivation represent only a small sliver of what the genre can do. In the right hands, the mystery novel becomes not only a thrilling cat-and-mouse game between a fiendishly clever murderer and a doggedly persistent detective, but also a commentary on the wider society that spawns, polices, and punishes murder. It is this wider view—the social view—at which the Scandinavians excel.

Perhaps we can attribute this in part to the small size of these far northern countries, their relatively homogenous populations, their stable cultural traditions—a setting, in short, in which murders (and especially serial murders) stand out starkly and beg for analysis. Or maybe this wider focus is connected to the firmly if mildly socialist perspective of even the most conservative Scandinavian governments, a view in which individual behavior contributes to or detracts from the public welfare. Possibly the dark, cold, long winters also have a role: With those extreme alternations between everlasting night and midnight sun, the Swedes, Danes, and Norwegians may be more likely than the rest of us to reflect on the role of environment in shaping character. The citizens of these countries also seem unusually alert to their own national pasts (unlike Americans, say, for whom the mid-twentieth-century is already History), and this in turn makes them more likely to seek cause and effect in these collective historical influences. In any event, what all these factors add up to is a worldview that places the criminal at the center of a social web. This is not necessarily what makes Scandinavian mysteries addictive—thatcan probably be attributed to the typical thriller qualities of suspense and surprise—but it is what makes them remarkably satisfying.

Jo Nesbø’s excellent books are the latest addition to this Nordic roster, which begins with the grandparents of all Scandinavian mysteries—the marvelous 10-volume Martin Beck series written by Per Wahlöö and Maj Sjöwall in the 1960s and 1970s—and descends through the estimable Henning Mankell, with his endearing Kurt Wallander figure, to the somewhat debased but still enjoyable level of Stieg Larsson. Nesbø differs from all these Swedes in that he is a Norwegian, so he’s playing his games (particularly his historical games) with a slightly different set of pieces. His moves, like those of his best predecessors, are subtle and complicated. His countermoves are even more so; and in order to keep up with the patterns of play, you really need to be able to keep the whole board in your mind at all times.

This, in fact, may be why Nesbø has thus far failed to capture the huge American audience that has glommed onto Stieg Larsson’s series. Nesbø asks you to know things about the world: about Norway’s involvement in the Second World War, about the nature of rural-urban migration in Scandinavia, about Eastern European gun-running, about the hierarchy of the Salvation Army, about DNA tracing, drug side-effects, and other medical technicalities, about …well, the list goes on and on.

You don’t have to know these things before you start reading Nesbø’s books. You can learn them from the novels themselves, if you are alert enough. The amount you are asked to absorb in any one volume, between the alternating strands of plot, the different perspectives of the various characters, and the welter of social, physical, and psychological information, is huge. Yet the absorption of all this stuff is so rapid, so intense, and—yes—so irresistibly addictive that, for those of us who have submitted ourselves fully to the process, it feels as if we are mainlining Nesbø, taking him in through our blood and our brains simultaneously. This is reading as you experienced it in childhood, without any gap between eye and mind, but with the added pleasures that adult plots and adult characters can bring.

Nesbø’s detective, who occupies center-stage throughout the series, is an Oslo-based police officer named Harry Hole. Like all appealing detective figures, Harry has many flaws. He’s an alcoholic with a tendency to surliness and even violence. He has trouble maintaining romantic relationships with women, though his closest friends and best partners tend to be female. He depends on the cooperation of others in the police force, but he is not a team player, and being his friend or colleague or even lover can be a dangerous proposition. He’s smart, and he has taste (references to excellent old movies and good pieces of music pop up in his reveries at key moments), but more than anything else he relies on a powerful internal engine he can’t control: his own intuition.

All this makes him nearly impossible for his superiors to work with, and as a result they often undermine him—sometimes understandably, sometimes with devious motives of their own. Like all great cop plots, the Harry Hole series depends on an expectation that the enemy will as likely come from within, and above, as he will from the world outside. This too, I suppose, is connected to that larger, broader perspective: the sense that the same institutional structures that shape the criminal world also shape (and mar) the world of the police.

Capitalizing, no doubt, on the enormous success of Stieg Larsson, Knopf is now issuing The Snowman, which is actually the seventh book in the Harry Hole series. Since it is crucial to read the series in order (because each plot refers to and in some cases hinges on the one before it, and Harry’s own life goes through transformations you will need to be a party to in order to understand the books fully), American readers will have some pleasurable background reading to do before they launch into this latest volume. The first two volumes, alas, have not yet been translated into English, so you will just have to live with those obscure references to whatever Harry did wrong when he was working on a case in South Africa.

The earliest book available to us Anglophones is The Redbreast; start there, and then move on to Nemesis and The Devil’s Star. These three form a trilogy in which the immediate case at hand (a cluster of contemporary murders that hark back to World War II, a string of increasingly violent bank robberies, and a series of symbolically similar but seemingly unrelated killings of women) gets resolved by the end of each book, but a deeper, darker case continues through all three. In solving each plot, Harry benefits from the special skills of his sidekicks—a woman named Ellen who can mentally draw every necessary connection between three random clues, and another woman named Beate who can recognize every face she’s every glimpsed—but these characters, despite their outlandish abilities, never seem hokey in any way, as the more bizarre achievements of Larsson’s Lizbeth Salander sometimes do. Character is important and largely credible in the Nesbø books, and that is part of what makes them consistently appealing. But it is their plots—brilliant conceived, carefully worked out, and complicatedly satisfying—that finally make them un-put-downable.

After The Devil’s Star comes The Redeemer, which intertwines a plot involving the Norwegian Salvation Army with a brief history of Balkan unrest. (A warning: You may have some trouble acquiring all these earlier books in America at this point; I had to alternate between remaindered hardcovers, imported British paperbacks, and Kindle editions in order to read the whole set.) And then at last we reach The Snowman, which is probably the most terrifying and certainly the most addictive book in the whole series. The novel’s storyline involves a series of gruesome murders, each heralded by the figure of a snowman, in which the victims are all mothers of young children; even to hint at what kinds of mothers they are would be to give away too much of the plot. Harry eventually exposes the serial killer with the help, but also sometimes the hindrance, of a new female sidekick, a glamorous, mysterious police officer named Katrin Bratt—and meanwhile his own relationship with his ex-lover Rakel and her son Oleg unravels on the side. Nesbø’s talent for complex, propulsive plotting reaches its pinnacle in this volume: I actually had to get out of bed in the middle of the night to finish reading it, because thinking about its plot strands made me hopelessly insomniac.

And yet The Snowman is also the volume in which the rot begins to set in. The baroque quality of its Grand Guignol ending signals—to me, at least—that Jo Nesbø is finally getting tired of Harry Hole. I would guess he has begun to find Harry more of a burden than a pleasure, and is starting to wish he could get rid of this financially rewarding, deeply disturbing alter-ego with whom he has somehow saddled himself.

It is the same process all great mystery writers go through—Conan Doyle with Sherlock Holmes, Mankell with Kurt Wallander. The despairing author realizes he has invented a character who has grown larger than himself, an uncontrollable figure who clambers across the supine authorial body as he makes his way into the arms of the demanding public. And the writerly impulse at this point is always the same: to destroy the detective in order to make his return impossible. Jo Nesbø has not yet reached this point, but he is getting there. In the book that comes after The Snowman, which is called The Leopard (due out from Knopf in 2013), he tries to kill off Harry three times, and the increasingly ludicrous violence makes the plot seem like something made for TV. If I can recognize the symptoms of decline, then so must Jo Nesbø. It is only a matter of time before the Harry Hole series will come to a grinding halt. So start reading now, before it’s too late.