STOCKHOLM, Sweden (AP) -- Stieg Larsson's story is nearly as exceptional as the plots of his crime novels.
Larsson was known in his native Sweden as an investigative journalist and a fervent campaigner against racism. But when he died of a heart attack at age 50 in 2004, he left behind the manuscripts of three books that would transform his legacy.
His first novel, "The Girl With the Dragon Tattoo," was published in Sweden a year after his death and was already an international success when it was released in the United States last year by Alfred A. Knopf and became a best seller.
More than 6 million copies of the book have been sold worldwide. An international study based on best-seller lists in the United States, Britain, France, Germany, Sweden, Italy, Spain and China ranked Larsson the second most popular fiction writer in 2008 after Khaled Hosseini, author of "The Kite Runner" and "A Thousand Splendid Suns."
"He takes you to a darker side of Sweden," says Paul Bogaards, director of publicity at Knopf. "A lot of Americans, when they think of Sweden they think of Saab and Volvo and Absolut. There are much darker undertones to Swedish society that Larsson hints at in all his novels."
Bogaards says the "The Girl With the Dragon Tattoo" has sold 200,000 paperback copies in the United States and orders are already coming in for the sequel, set for release in July. The third installment is currently being translated into English. A movie based on Larsson's books, featuring a tattooed computer hacker and a disgraced journalist, will hit screens in Sweden later this year.
Larsson never got to experience the success.
"He would have been overwhelmed, just like us, and proud and happy," says Eva Gedin, head of publishing at Swedish publisher Norstedts.
Gedin, who worked closely with Larsson, recalls how the author delivered the manuscripts of the first two books in a plastic bag as he was about to finish the third. Norstedts signed a three-book contract right away — an unusual deal for a debuting fiction writer.
"He had a great deal of positive responses from us at the publishing house and ... by key people in the book store industry who said that this was brilliant," Gedin says.
Larsson is the latest of many Swedish crime writers to win international acclaim, from the team of Maj Sjowall and Per Wahloo in the 1960s to the more recent Henning Mankell, creator of the gloomy detective Kurt Wallander in such books as "Faceless Killers," "Sidetracked," "Firewall" and "Before the Frost."
The Scandinavian crime writing tradition also includes Denmark's Peter Hoeg, whose "Smilla's Sense of Snow" became an international best seller in the 1990s and a movie starring Julia Ormond, Vanessa Redgrave and Gabriel Byrne.
Set in a scenic Nordic landscape of serene lakes and lonely red cabins, Larsson's trilogy follows computer hacker Lisbeth Salander and journalist Mikael Blomqvist as they get entangled in a series of murder mysteries. Like Mankell, Larsson weaves in social commentary, with democracy and women's rights as prominent themes.
That, the exotic setting and an introspective streak are what set apart Swedish crime writing in a genre dominated by U.S. and British novelists, says Maxine Clarke, a critic at the Britain-based Web site Euro Crime, which specializes in European crime literature.
In Swedish crime novels, Clarke says, "one gets to know the characters' domestic lives and concerns as background to the plots — one feels they are real people rather than, in some other thriller genres, characters who only seem to exist to take part in the novel's main story."
Swedish crime literature has become a phenomenon in Europe, so much so that the Germans have invented a new word for it: "Schwedenkrimi." And the southern town of Ystad offers popular "Wallander" tours, showing visitors the neighborhoods where Mankell's sullen detective solves one grisly crime after another.
Still, Mankell dislikes talking about a Swedish crime fiction genre, saying that above all he has been inspired by Sherlock Holmes and classical Greek drama.
"Of course, I also read Sjowall-Wahloo but one must not forget that they in turn were very influenced by Ed McBain, and who influenced Ed McBain? He was absolutely influenced by Sherlock Holmes," Mankell says.
As for Larsson, he primarily drew inspiration from British and American authors such as Sara Paretsky, Val McDermid and Elizabeth George. Salander's character, however, was inspired by the strong-willed redhead Pippi Longstocking in the children's books by the late Astrid Lindgren.
"What would she have been like today? What would she have been like as an adult? What would she be called? A sociopath?" Larsson told book store industry magazine Svensk Bokhandel in the only interview he ever did about his crime fiction. "I created her as Lisbeth Salander, 25 years old and extremely isolated. She doesn't know anyone, has no social competence."
In "The Girl With the Dragon Tattoo," Salander joins Blomqvist at a small, remote island in central Sweden to help him solve the disappearance 40 years earlier of the niece of a retired business tycoon. The duo soon uncover disturbing clues suggesting she was killed by a serial killer consumed by hatred toward women.
Larsson's second book, "The Girl Who Played With Fire," topped the hardback fiction charts in Britain in January and is set for release in the United States in July. The book focuses on a sex trafficking case, while revealing dark secrets about Salander's past.
As the editor of anti-racism magazine Expo and contributor to its British counterpart Searchlight, Larsson received death threats for his campaigns to expose far-right extremists in Sweden. Expo was founded in the mid-'90s, when neo-Nazi groups carried out a series of violent attacks against immigrants in Sweden. Writing the stories about Salander and Blomqvist became a relaxing hobby that took his mind off work.
"I think this thing of writing fiction was pure enjoyment for him — pleasurable and relaxing and fun, and something which didn't demand the same extreme fact checks as when he wrote for Expo," Gedin says.