Lisbeth Salander, the androgynous heroine and tattooed computer hacker from the Millennium series, is set to grip readers' imaginations again as the fifth volume hit bookshelves on Thursday.

The new book by the 55-year-old David Lagercrantz, titled "The Girl Who Takes an Eye For an Eye", reveals more secrets surrounding the mysterious Salander's troubled childhood and the true meaning behind her iconic dragon-shaped tattoo.

When Lagercrantz's fourth tome "The Girl in the Spider's Web", which received mixed reviews, was launched in 2015, he was met with overcrowded press conferences, journalists queuing for interviews and midnight book signings.

The launch of the fifth volume was however more low key -- Lagercrantz was to make no public appearances until his book tour kicks off on September 10.

"The Girl in the Spider's Web" was the first sequel to the trilogy conceived by Stieg Larsson, who became one of the world's best-loved crime writers.

But Larsson's fame came posthumously. He died at the age of 50 from a heart attack in 2004, a year before the release of the first book in the series, "The Girl With the Dragon Tattoo", followed by "The Girl Who Played with Fire" (2006) and "The Girl Who Kicked the Hornets' Nest" (2007).

- 'More banal' -

While many Larsson fans rejoiced over the continuation of the trilogy when Lagercrantz was selected to write the fourth book, some -- including Larsson's longtime partner Eva Gabrielsson -- vehemently opposed him taking up the torch, calling him "a totally idiotic choice".

"Everybody was very curious. We wanted to see if he was going to succeed," Lund University literature professor Kerstin Bergman told AFP.

"It was a good crime novel, very different from Stieg Larsson's (book)," she said, referring to the fourth book, which sold six million copies in 47 countries, compared to 80 million for the trilogy.

But as much as readers can't get enough of Lisbeth's punk-rock feminism, the hype over Lagercrantz's continuation of the series is not what it used to be.

"Now it's more banal. People love the characters and want to read about their adventures," said Bergman, a specialist in Nordic Noir, a genre that mixes crime fiction and social criticism.

Lagercrantz intends to transform the series and win over his critics.

But he said Thursday he was nervous about how the new book would be received.

"You don't have to be paranoid to go crazy the day before a book release... I'm feverish," he told Swedish Radio.

But he had more fun writing this book than the last one.

"Last time I felt utter and total fear. That fear wasn't such a bad thing, as it elevated me. But this time I dared a bit more ... It's Stieg Larsson's universe and his characters but I dared to put more of me into it this time. It was more fun to write."

At Stockholm's Akademibokhandeln bookstore, a display featuring the book was placed right inside the entrance.

Anki, a shopper in her 40s, was one of those who rushed out to buy a copy early Thursday.

"I read the trilogy and Lagercrantz's first book, and I'm really curious about this sequel. I think he's managed to capture the mood and Salander's personality," she told AFP.

- 'More sensitive character' -

In "The Girl Who Takes an Eye For an Eye", Lagercrantz throws Salander "into the worst prison for women, where she immediately encounters a lot of problems," he told AFP in the spring.

Alongside Lisbeth, readers will find Mikael Blomqvist, a talented investigative journalist who's also worn out by life.

As the duo investigate the abuse of power and the social injustice that Lisbeth has gone through, they try to overcome new obstacles.

Lagercrantz has admitted that bringing this young woman with a dark past back to life in the books caused him headaches. Contrary to Stieg Larsson, Lagercrantz said he would have chosen a heroine with a "sweeter, nicer and more sensitive" character.

In his relentless quest for inspiration, Lagercrantz wrote on his publishing house's website that he interviewed "doctors, archivists, robotics researchers, Bangladeshi bloggers threatened to death" and visited a prison in southeastern Sweden.

"The Girl Who Takes an Eye For an Eye" is to be published in 34 countries. It was released on Thursday in 26 of them, including Britain, the United States, Germany and France.

Lagercrantz has also signed on to write the sixth book, which he insisted would be his last in the series.