You join us near the end.

"Our perception of the Second World War is heavily influenced by the things that Churchill wanted to look at. He's saying 'Look over here. Here's the spotlight. But don't see what we are doing over there. Don't look at that, because that was discreditable' ..."

I believe it's as Nick Harkaway ­compares Winston Churchill's historical writing to the work of a film director that I begin to imagine I'm actually in the middle of a Harkaway novel. One that - as Harkaway novels tend to do - circles and circles and then shoots off in an unexpected direction before doubling back and circling again. Plots that double up as perpetual dazzle machines.

Our conversation has a similar giddy thrill to it. Already this hour we've had a discussion of superheroes, the net importing of prisoners into the Danish prison system from abroad because its own prison population is shrinking, parenting strategies, the cultural theories of critic Robert Warshow, rendition, the fact that you can't draw a line under history, John Le Carre (for obvious reasons, or reasons that will become obvious if you're not already aware of them), the concept of a place called Null Island (the concept is real, the island is not), Francois Truffaut and the misuse of auteur theory.

The latter came 20-odd minutes before this "Churchill as director" idea surfaces, but in my befuddled head the two are instantly connected and I begin to believe all of this stuff we've talked about is connected, is part of a complex, interconnected narrative engine that I've somehow got lost inside.

Which is probably true as it goes. The narrative engine that is Harkaway's brain. We are sitting in his home, a higgledy-piggledy pile that sits off the street in Hampstead that could conceivably be mapped onto its owner's imagination. "If you look around the room you can see how my head works," he says. "Clutter and junk but poking out of it is stuff that's really interesting. That's how it works for me."

And it does work, as his previous two novels The Gone-Away World and Angelmaker show. We're here today to discuss Harkaway's third novel Tigerman, a riff on the aforementioned superheroes, post-colonial politics, 24-hour news culture and fatherhood among another half-dozen things (at least). It's the most restrained book he's written so far, believe it or not. "I suppose the journey from Gone-Away World through Angelmaker to Tigerman is a journey of concision," he admits. "Gone-Away World was a shotgun blast, an explosion out of the box I'd put myself into writing film scripts. Tigerman is shorter, tighter, more crafted."

It's more "real" too he says, although considering it contains a former British soldier turned minor diplomat called Lester who dresses up in a tiger costume to fight a possibly fictitious criminal mastermind, it's conceivable his definition of reality might not align with yours.

But then, he says, the world isn't real in the way literature so often defines it, "the sort of new puritan dogma that almost says you report only the prosaic, that you can't dress it up, you can't do burlesque, I find very strange. Literally this morning I was sitting in the cafe across the road and it transpires that the waitress working there was a Hungarian police officer for 11 years, and suddenly I'm talking to her about what it's like being a Hungarian police officer.

"Now, the stuff she's describing is completely off the chart in terms of crazy. Of course it is, because police officers everywhere experience the completely bizarre all the time. So, does that mean I can't put that in a book even though it's true? No, that's ridiculous. The addiction to the illusion of reality, the broadest, flattest reality, I think, is harmful and I think it's tedious."

Tedious is the last word you could use to describe his own writing - or conversation. He tops his intellect in a circus ringmaster's hat. But for all the entertainment to be had from the reading, the serious stuff is in there. Ask him about the genesis of Tigerman and he begins to talk about the (real) island of Diego Garcia, a UK territory in the Indian Ocean on which two rendition flights landed in 2002. (Last month, after years in which rendition claims about Diego Garcia had been disputed by the UK government, claims emerged the Americans ran a "black" jail on the island.)

"My wife runs the charity Reprieve and so rendition, droning and capital punishment are very much the topics of our dinner table because of that. And then I had this stuff going on with this notion of a paternal relationship because my wife was pregnant."

In the novel Lester is a wannabe father to a superhero-obsessed boy who may or may not have his own family. In that sense, like its predecessor Angelmaker, it's another novel about fathers and sons, though in this case the relationship is more provisional. At which point, maybe it's time for an origin story. What, I ask Nick Harkaway, did the idea of the writer represent in your family growing up? "Obviously it was my dad," he tells me. Harkaway - real name Nicholas Cornwall - is John Le Carre's son (forgive me if you'd already heard that plot twist). And so, "stories were the currency of our household," he says.

Harkaway, now in his early forties, grew up in a house where writing was seen as a job of work. "You do it when you're hungover, you do it when you don't feel like it, you do it when you're upset."

Did he worry about choosing the same career as his father given that Le Carre was already so conspicuously successful - both critically and commercially? "I worried about it a long time, I think, subconsciously. I think the reason I wrote screenplays for nearly a decade was because it was my territory. I could stake that out. That was a completely ineffectual strategy. I guess we have similar concerns, which is inevitable since I grew up in that house. I feel what I do is sufficiently different within the writing world and my concerns beyond the obvious geopolitical ones are sufficiently different that I don't worry about it. Now I just get on with it."

Is Angelmaker - with its SOE agents and a son's discovery of his father's hidden past - your version of A Perfect Spy? "Ha! No. You're right obviously in that it's about fathers and sons and dynastic transmission, but that came out of the architecture of the book which is about perceptions of history.

"In the aftermath of September 11 you can't - as Tony Blair was so fond of suggesting - draw a line under historical events. They don't go away. They come back. Nobody, not even America in this world, has the power to draw a line under an issue. So if you are seen by the rest of the world to commit a sin, that sin will hang around. The idea that history was a kind of well of terrible crap that we all live over, and every so often something monstrous comes up into the cellar, was what Angelmaker was about."

In a sense he makes the same point when talking about superheroes. "When you look at Batman he's editing the rhetoric of Batman. He's editing the human concept set. He's demonstrating to the criminal that someone will come and find them. That there is justice, that justice can be postponed but never entirely eluded."

Superman represents faith, Batman determination. This takes him to Wesley Clark, former allied commander of Nato who, on arriving in the Balkans during the ethnic conflict that scarred the area in the 1990s, effectively said 'we're here to show that man cannot do this, that ethnic cleansing was not a concept in the set of human actions available in politics'.

"A wonderful idea which we failed to deliver on," notes Harkaway. "The consequence of that is the rhetoric used by Britain and America in the wake of 9/11 to justify the unpleasant things that we did is now used by Putin in Russia about the Ukraine, by all the states that torture their own citizens."

We're a long way from auteur theory here, aren't we? Harkaway is a writer who nests big ideas inside bigger ideas. He's aware of the dangers of the seduction of narrative, but there's a defence of stories too. "That apart from anything else they are a statement of identity, of the self. They allow us to communicate who we are. It's how we bridge the gap between two skulls."

Nick Harkaway is a writer. Start here.

Tigerman by Nick Harkaway is published by William Heinemann, £16.99