Not even Stieg Larsson could've dreamed up "The Girl Who Fought for a Share of the Inheritance."

But five years after his untimely death and millions of book sales later, the Swedish crime writer's estate is caught in a bitter feud worthy of one of his thrillers, complete with a strong-willed female protagonist, a murky bog of possible villains and a plot that has transfixed this Scandinavian country.

It's a saga of love, literature and the law. Of blood versus bond, pitting Larsson's relatives against his lifelong companion for control of a posthumous publishing juggernaut that shows no sign of slowing.

As anyone who's stepped into a bookstore lately knows, Larsson was the author of the darkly convoluted crime novels "The Girl With the Dragon Tattoo" and "The Girl Who Played With Fire." Last year, industry watchers named him the world's second-bestselling writer.

The third installment in his "Millennium" series, "The Girl Who Kicked the Hornets' Nest," is due out in the United States in May and is one of the most hotly anticipated titles of 2010. Hollywood, inevitably, is interested.

Critics and fans have swooned over the books' dense plotting, their evocative descriptions of the seamy underbelly of society and the unlikely heroine, Lisbeth Salander, a bisexual, emotionally wounded and almost superhumanly gifted computer hacker and avenging angel rolled into one.

Larsson, though, never lived to see his success. A workaholic and nonstop smoker, he collapsed and died Nov. 9, 2004, after climbing seven flights of stairs to his office because the elevator was out of order. He was 50.

His first novel, written as an escape from his job as a crusading journalist, was months away from hitting the shelves. Manuscripts for the next two were already in the hands of his publishers, and a fourth was in progress.

Because Larsson never made a will, everything he owned, including the rights to his work, passed to his father and brother.

The woman who was at his side for 30 years inherited nothing. She and Larsson never married -- a fact that has exacted an unforeseen price. Swedish law does not recognize common-law relationships, and she is not entitled to a penny of his estate.

Larsson couldn't have written a better cliffhanger.

They had certainly intended to tie the knot when they were younger, said Eva Gabrielsson, the love of Larsson's life. But two things conspired against them, she said.

"We did plan to get married, in 1983, except the United States did something bad then: You invaded Grenada," the longtime leftist said recently over coffee.

She and Larsson had visited the Caribbean island nation a few years before in support of its left-wing government. After the U.S. invasion led to the regime's overthrow, the couple decided to go back and investigate the situation, so marriage plans were put "on hold," said Gabrielsson, now 56.

Their devotion to left-wing causes had brought them together: They were 18 and living in northern Sweden in 1972 when they met at a rally against the Vietnam War.

It was Gabrielsson's first demonstration. Larsson, already a young leader in the local antiwar movement, spotted the pretty new protester and quickly set about recruiting her, Gabrielsson recalled with a chuckle. Two years later, they were living together.

The couple moved to Stockholm in 1977 so Gabrielsson could pursue her studies in architecture. Larsson worked for a while at the post office, but eventually found an outlet that combined his two consuming passions: writing and combating fascism.

First for the British anti-fascist magazine Searchlight and then for Expo, the Swedish equivalent he helped found, Larsson campaigned against the neo-Nazis who were gaining ground in his homeland. They were known to be a violent group, incriminated in various bombings and killings.

Death threats soon began coming Larsson's way, so serious that, in 1994, the government tried and convicted the editors of a far-right magazine that published Larsson's photo and address and called him a traitor who had to be stopped.