Eva Gabrielsson, the partner of the late Stieg Larsson, has described David Lagercrantz as an "idiotic choice" for the job of writing a sequel to Larsson's Millennium trilogy. Without putting it in those terms myself, I did wonder - after reading Lagercrantz's novel Fall of Man in Wilmslow - which uses the death of Alan Turing as the springboard for a glacier-paced, ludic and philosophical crime novel - if he was the right man to reproduce Larsson's straightforward mixture of kiss-kiss-bang-bang storytelling and strident social commentary.
But as I read Lagercrantz's The Girl in the Spider's Web, I found that I kept forgetting that I wasn't reading genuine Larsson. I have read uncountable numbers of these ersatz sequels in which one writer appropriates another's characters, but never one that enabled such close replication of the experience of reading the original author.
Before his untimely death in 2004, Larsson had made it clear that the Millennium trilogy was the inauguration of a series that would extend to eight or 10 volumes, and so over the years his fans have often speculated about what those books might have contained: what would his tattooed, sociopathic heroine, the ace hacker Lisbeth Salander, get up to in a post-WikiLeaks world?
Well, now we know. The book opens with what seems like an authentically Larssonian scenario: Salander becoming America's Public Enemy No1 after she hacks into the National Security Agency's intranet and sends them a message telling them to "stop with all the illegal activity".
Meanwhile, Salander's old sidekick, journalist Mikael Blomkvist (more world-weary and pot-bellied than ever but naturally still catnip to the ladies) is struggling to adapt to a world even more infantilised and trivial than it was when Larsson died in 2004.
Because he refuses to have Facebook and Twitter accounts, rival journos are painting him as a washed-up dinosaur, and the big media company that has bought a stake in Millennium magazine are demanding less investigative reporting and more articles about "celebrities and premieres".
He needs a scoop to save the magazine, and it comes in the form of a breakneck plot involving a murder attempt on an 8-year-old savant who cannot talk but is an ace code-cracker, and a plot to steal a dysfunctional scientist's groundbreaking work on super-intelligent computers - the phrase "Turing test" is never mentioned, but the hero of Lagercrantz's previous novel is clearly the tutelary spirit of this one.
We are also treated to an appearance from a character from Salander's past who has often been alluded to but not previously appeared: a less brave author might not have gone down this route for fear of anti-climax, but Lagercrantz pulls it off.
He has even managed to appropriate some of Larsson's imperfections, including a capacity for sometimes being boring: as in the original books, there is far too much detailed information about the lives of fairly minor characters.
But one devours Larsson's books for the plots, the action, the anger, and most of all for Lisbeth Salander, a character who resembles Sherlock Holmes or James Bond in being so powerful because she is a brilliantly realised myth rather than a psychologically convincing character study.
Lagercrantz has caught her superbly, and expertly spun the sort of melodramatic yarn in which she can thrive.
Ace hacker returns
The Girl in the Spider's Web
by David Lagercrantz,
by George Goulding