The sequel to the Girl With The Dragon Tattoo series has been shrouded in such secrecy the novel is being written on computers with no internet connection to avoid any leaks. The Girl In The Spider's Web, published worldwide on August 27, will be the fourth installment in the best-selling Millennium crime trilogy by Swedish author Stieg Larsson. The book was completed in November by David Lagercrantz based on a plot outline left by Larsson before he died of a heart attack in 2004 aged 50. Mr Lagercrantz, known for co-authoring Swedish football star Zlatan Ibrahimovic's autobiography, said the publishers have gone to extreme lengths to keep the novel under wraps. However, Norstedts did yesterday reveal that it kicks off with an artificial intelligence intrigue involving a U.S. spy agency. Under wraps: The sequel to the Girl With The Dragon Tattoo series by Steig Larsson (left) entitled The Girl In The Spider's Web (right) has been shrouded in such secrecy it is being written on computers with no internet . The 500-page sequel takes up the story of tattooed computer hacker Lisbeth Salander and journalist Mikael Blomkvist, whom she helps solve a murder mystery  in the first book in the series. Mr Lagercrantz said he, the editors and translators were subject to similar kinds of espionage-style secrecy, reportedly working on computers disconnected from the Internet to avoid leaks. He told the Dagens Nyheter daily: 'If you write about Lisbeth Salander its easy to get a little paranoid. 'You realise what opportunities there are to hack computers. 'It was a little awkward. 'Every time I needed to Google I had to do it on another computer. And we used code words - like our own little spy world.' Its British publisher, MacLehose Press, which has unveiled the front cover showing Salander with her dragon tattoo and wearing punk trousers, said they have given strict instructions to follow suit. Taking up the mantle: The book was completed in November by David Lagercrantz (above) based on a plot outline left by Larsson before he died of a heart attack in 2004 aged 50 . Christopher MacLehose told The Guardian: 'The Swedish original publishers Norstedts have put everyone on notice that no particle of this book can be shared with anybody. 'There'll be no review copies in any language before it's launched on 27 August... nobody will be in a position to beat the ring of steel around this book.' The novel is called Det som inte dödar oss in the original Swedish - or What Doesn’t Kill You - but given a different title for the English version. It is being translated into 38 languages. Setting the scene, Norstedts publishing house wrote on its website: 'One night professor Frans Balder, a leading authority within AI (artificial intelligence) research, calls up Blomkvist. 'Balder says he has world-shattering information on U.S. intelligence services... had contact with a female super hacker, who bears a certain resemblance to a person Blomkvist knows well.' Saddened: Eva Gabrielsson has said Larsson would have been 'furious' about the release of The Girl In The Spider's Web, the fourth book in the Millennium series which began with The Girl With The Dragon Tattoo . Until now the publishers had remained tight-lipped about the plot, only saying that it would continue the story of the trilogy's heroine, which has sold more than 75 million copies worldwide. The book has been given the blessing of Mr Larsson's estate, but not from his long-term partner. Eva Gabrielsson said last month that the journalist, who co-founded the anti-racism magazine Expo in Sweden, 'would be furious' if he knew someone else was writing his story. Gabrielsson, who lost a bitter battle with the late author's family to manage his work, added that Lagercrantz was 'a totally idiotic choice' as he lacked Larsson's left-wing activist background. Norstedts have compared the planned release on August 27 of the book in at least 35 countries to the global splash made by Dan Brown's sequels to the 2003 'Da Vinci Code'. At the time of his death, Larsson reportedly had plans to write at least another seven novels.
The Girl In The Spider's Web is fourth installment in Stieg Larsson's series . Written and translated on computers with no web connection to avoid leaks . Plot kicks off with artificial intelligence intrigue involving a U.S. spy agency .