Armed with an image glimpsed in a tube station of a locksmith with a spray can marked “universal solvent”, a figure from the far end of human development and a crime, in 2013 he hit upon the germ of an idea and “just started writing”. If it was good enough for Gibson, Harkaway told himself, he should give it a try. Harkaway was talking to William Gibson – a writer he has admired since Neuromancer blew his teenage mind – and he learned that Gibson doesn’t plan his fiction, but just gets a concept and follows the story. But the intricate construction of this 700-page novel emerged as something of an accident. Harkaway has chosen an unashamedly literary route through this tangled web, splitting the narrative between interlocking points of view, the prose sometimes shattering under the pressure of the interrogation. When the interrogation goes wrong, an inspector dives into the memory files extracted from her brain and finds herself submerged in a series of other minds, leading her to question the foundations of the surveillance state. A woman living in defiance of a regime built on constant connection is called in for questioning. His fourth novel, Gnomon, is no exception, with his near-future detective embarking on an investigation that races through privacy, encryption, alchemy, a sociopathic post-human intelligence and Bach’s Musical Offering. The breakneck whirl of Harkaway’s conversation is a bit like his fiction, ideas fizzing off in every direction as it hurtles along.

“I’ve strayed again … what was the question?” People would walk out into the street and make sure their neighbours are OK, the way they do after earthquakes.” He stops, looks around the light study at the top of his house in Belsize Park, north London, and tries to work out how he’s got from the all-seeing surveillance at the heart of his latest novel to historical materialism. ‘If everybody was incredibly committed to acts of kindness and charity in a ubiquitous circle of love and whatever,” Nick Harkaway waves his hands as the words come tumbling out, “we’d be living in a utopia now.

Gnomon by nick harkaway