But their journey in the fourth book of Stieg Larsson's best-selling "Millennium" crime series is a mystery. The book was left unfinished on the author's laptop when he died suddenly in 2004 at age 50.
Only two people know about the content of the manuscript: Larsson's longtime partner Eva Gabrielsson, who has refused to talk about it and won't reveal the whereabouts of the last installment in the series, which started with "The Girl With the Dragon Tattoo"; and Larsson's friend John-Henri Holmberg, who received an e-mail about the book from Larsson less than a month before his death on Nov. 9, 2004.
Gabrielsson is in a legal deadlock with Larsson's family over the author's estate.
Holmberg said that Larsson was 320 pages into the fourth book and had planned to complete it by December.
"The plot is set 120 kilometers north of Sachs Harbour, at Banks Island in the month of September," Larsson wrote in the e-mail, which Holmberg made available to The Associated Press. "According to the synopsis it should be 440 pages."
Holmberg, who first met Larsson at a science-fiction convention in the 1970s, said his friend had finished the beginning and the end of the story but had to find another plot for the middle.
"Did you know that 134 people live in Sachs Harbour, whose only contact with the world is a postal plane twice a week when the weather permits?" Larsson wrote. "But there are 48,000 musk-ox and 80 different types of wild flowers that bloom during two weeks in early July, as well as an estimated 1,500 polar bears."
Holmberg says he doesn't know more than that about the plot, but that Larsson had wanted all his books to follow a theme about women.
He says the author probably had a detailed outline of the story among his notes, making it possible for someone such as Gabrielsson who worked closely with Larsson on the first three books to complete the manuscript.
However, Holmberg points out that completing the story would have to be done soon so it doesn't become just a "historic curiosity."
"The risk ... is that it turns into one of those idiotic things like 'The Mystery of Edwin Drood,'" he said, referring to Charles Dickens' half-finished final work that many other writers tried to complete after his death.
"Give it 10 years" after the last Hollywood film is released, he said. "After that, there will be no meaning to it. And I believe Stieg was focused on having some kind of meaning in what he wrote."
The posthumous completion of an unfinished work is an old publishing tradition, from Edith Wharton's "The Buccaneers" to Robert Jordan's "The Gathering Storm," which came out last fall.
For publisher Norstedts getting the last book out in print could be a gold-mine.
So far, Larsson's trilogy about a darker side of Sweden, where a tattooed computer hacker and journalist get entangled in murder mysteries, sex trafficking scandals and secret government units, has sold more than 30 million copies worldwide and is selling more than 50,000 copies a day in the United States. A Swedish-language film of "Dragon Tattoo" came out last year and was a surprise hit. Now filming begins next year on a Hollywood remake.
Patricia Bostelman, vice president of marketing for Barnes & Noble Inc., said there was a strong interest in more fiction from Larsson, but cautioned that would depend on how much of the "Larsson experience" was offered.
"Delivering that experience will depend on a number of factors including how much of the manuscript still needs to be completed and if the author or editor completing it is able to capture Larsson's voice," Bostelman said. "If the narrative is as strong as the previous books and they can get the voice, then we think a fourth book would be successful."
For now, Norstedts doesn't want to comment on the possibility of a fourth book.
"The question about the fourth manuscript is entirely hypothetical," head of publishing at Norstedts, Eva Gedin, said. "We have never studied this manuscript and therefore don't know if it exists, how much has been written and if so what shape the manuscript is in."
Since Larsson's death the whereabouts of the fourth manuscript has been clouded in mystery. Gabrielsson who is involved in a thorny conflict with the author's father and brother, Erland and Joakim Larsson initially acknowledged she had the laptop containing the fourth manuscript. However, in an interview with Swedish tabloid Aftonbladet in June, Gabrielsson said she doesn't want to see any other book in the Millennium series published and said she does not have the manuscript. Joakim Larsson said in an e-mail that he doesn't know where it is now.
The reason for the dispute is a Swedish law that stipulates partners aren't entitled to inherit from each other unless they are married or have special wills. Like many Swedish couples, Larsson and Gabrielsson never married, which meant Erland and Joakim inherited everything after the author's premature death.
Gabrielsson has said she isn't interested in the money but wants to have the final word on how Larsson's work is used, a demand the Larsson family hasn't accepted.
For a long time, negotiations to settle the dispute were stalled as both parties threw accusations at each other in the Swedish media.
Last December, the parties' lawyers resumed talks but they collapsed again in mid-June.