The scene toward the close of Stieg Larsson's "The Girl Who Played With Fire" is gut-wrenching: Two men tie up and take turns raping a 16-year-old prostitute who has been lured to Sweden in a sex trafficking ring.
The wildly popular author of the "Millennium" trilogy, which also includes, "The Girl With the Dragon Tattoo" and "The Girl Who Kicked the Hornet's Nest," is graphic in his descriptions of violence against women, and now his closest friend reveals why.
Larsson had his own dark secret. At the age of 15 he witnessed a gang rape and never intervened, according to longtime friend Kurdo Baksi. Days later, ridden with guilt, Larsson asked the victim for her forgiveness, but she refused.
That girl was Lisbeth, the name later given to the tattooed, Asperger's-afflicted Lisbeth Salander -- heroine of Larsson's three novels.
The guilt over failing to act haunted Larsson his entire life and fueled the subject of his crime novels, according to Baksi, who wrote "Stieg Larsson: Our Days in Stockholm," a soon-to-be published memoir devoted to setting the record straight about Larsson's real-life commitment to social justice.
"It was his way of apologizing," said Baksi, who is devoted to avenging the gang rape that haunted his friend for so many years.
So far, he hasn't found their identities, but has pledged to continue the search.
"I don't even know if Lisbeth is alive," said Baksi. "But it's very important to me."
Larsson, in real life an investigative journalist who was a tireless advocate for women, died of a heart attack at the age of 50 in 2004.
His books chronicle the adventures of the quirky, computer hacker heroine Lisbeth Salander and the crusading editor Michael Blomkvist, who get entangled in murders, sex trafficking and corporate crime.
Published posthumously, the books have sold more than 30 million copies worldwide and more than 50,000 copies a day in the United States.
The Swedish film, "The Girl with the Dragon Tattoo," came out in 2009 and an American remake with Daniel Craig is set for release in 2011.
The Swedish title for first book and film is "Men Who Hate Women," a theme that pervades all three books and his previously published works.
Baksi and Larsson met in 1992 through socialist efforts and later grew close as editors. Baksi, editor of the antiracist magazine, Black and White, helped the writer found his investigative magazine, Expo, the model for the trilogy's Millennium.
The magazines later merged and they worked together almost daily. "He called me his little brother," said Baksi, now 45.
"He was a guy who was always with you," said Baksi. "It was an "unconditional friendship."
"Stieg told me, 'I need to write this book'," he said. "'It's really important to me. I saw a rape and I didn't do anything. I felt terrible about what I had seen.'"
The incident happened in 1969 at a camping site in northern Sweden. Three of his friends assaulted a 15-year-old girl as Larsson watched.
"Her screams were heartrending, but he didn't intervene," writes Baksi in his book. "His loyalty to his friends was too strong. He was too young, too insecure. It was inevitable that he would realize afterwards that he could have acted and possibly prevented the rape."
Larsson's apology fell on deaf ears. "In the north of Sweden, nobody forgets," said Baksi.