It is unlikely that you’ve heard of the Swedish author Stieg Larsson, but that’s about to change. Larsson is a publishing sensation, an accomplished crime writer who seemingly came from nowhere and sold millions of books in Scandinavia. His journalist-hero Mikael Blomkvist could hardly be more different from Henning Mankell’s gloomy Inspector Wallander, and his own life story sounds like fiction.

Before he started writing novels, Larsson was a campaigning journalist. He dedicated his life to opposing racism, contributing for many years to Searchlight, the British anti-fascist magazine. At the same time, he was writing fiction and eventually sent one of his novels to a Swedish publisher, who snapped it up.

The Girl with the Dragon Tattoo is the first volume in the Millennium trilogy, named after the magazine where Blomkvist works. In Sweden, the trilogy’s sales have topped 2m, while in Denmark it has out-sold everything except the Bible. Tragically, Larsson did not live to enjoy this success; he died of a heart attack, aged 50, before the novels were published.

Given all this, it is hard not to approach the novel with heightened expectations. It begins at a low point in Blomkvist’s career as he loses a criminal libel case brought by a Swedish tycoon, the head of the powerful Wennerstrom Group, and faces a short prison sentence. His reputation is in tatters and the future of his magazine in jeopardy when he is called by a lawyer acting on behalfof a rival industrialist, Henrik Vanger. Vanger lives on the remote Norrland coast and when Blomkvist reluctantly agrees to visit him – anything to take his mind off the libel case – he is surprised to be offered a job. Vanger wants Blomkvist to find out what happened to his great-niece Harriet, who disappeared almost 40 years before, and suggests that the disgraced reporter uses the pretence of ghosting Vanger’s autobiography as cover.

As crime-fiction fans will quickly recognise, Harriet’s disappearance is a classic locked-room mystery; Blomkvist, who is an avid reader of detective novels, describes it as “a sort of locked-room mystery in island format”. The Vanger family live on Hedeby island, which is linked to the nearby town of Hedestad by a single bridge; on the day that 16-year-old Harriet went missing, a car collided with an oil tanker on the bridge, cutting off the island for several hours. Harriet was last seen shortly before the crash and it was only much later that day, when the debris was removed, that her absence from the island was noted. An increasingly frantic search took place, but her body was never found.

Blomkvist is reluctant to take the job until Vanger provides two incentives he can’t resist: the industrialist is willing to back Millennium financially, and he has dirt on Wennerstrom that he will hand over when the investigation is complete. It is a brilliant set-up, which takes Blomkvist out of his usual city environment and places him in a small town that is essentially owned by the Vanger family.

The parallels between Blomkvist’s interests and those of his creator converge in the Vanger family’s Nazi past, exposing elements of Sweden’s 20th-century history that may be unfamiliar to British readers. Three of Vanger’s brothers were Nazis, supporting Per Engdahl’s fascist movement, and the rest of the family is pretty unsavoury in one way or another. But Larsson’s other great preoccupation was violence against women, and the scarcely believable horrors Blomkvist unearths are as rooted in misogyny as they are in fascism.

This is reflected in the novel’s original (and stronger) Swedish title, Men Who Hated Women. The change is unfortunate for another reason, drawing attention to the book’s most problematic aspect, a young woman called Lisbeth Salander (the owner of the dragon tattoo) who becomes crucial to Blomkvist’s investigation. Salander is slight, serially abused, a little autistic and a brilliant computer hacker; originally employed to investigate Blomkvist, she attaches herself to him with the ferocious loyalty of a tamed feral cat and plays a crucial role in uncovering Harriet’s startling fate.

It’s not hard to see why Larrson invented her; if Blomkvist is his fictional alter ego, Salander is confirmation of his belief in a woman’s capacity to survive the most dreadful abuse. She isn’t so much a character as a revenge fantasy come to life, powering her way through the novel like the heroine of a computer game and undermining its gritty realism.

That said, The Girl with the Dragon Tattoo is a memorable debut and deserves most of the hype with which it is being published in this country. Crime fiction has seldom needed to salute and mourn such a stellar talent as Larsson’s in the same breath.

THE GIRL WITH THE DRAGON TATTOO by Stieg Larsson, translated by Steven T Murray
Maclehose Press £14.99 pp534

Times Recommends

• The 100 Best Books of the Decade
• The Times picks the 50 best paperbacks of 2009
• The conversation: James Ellroy