It’s little wonder Wolfe is transfixed by the meat market, but beyond this, Smithfield provides a powerful literary touchstone.

Charles Dickens set a famous scene in Oliver Twist here, and Parsons tells me that it was only when he was in Smithfield, waiting for inspiration to strike, that he discovered the scene inscribed in stone.

The lost children of Oliver Twist and Great Expectations, as well as the Dickensian leitmotifs of unexplained dubious wealth, prostitution and murder, chime powerfully with Parsons’ own themes here. But far from a dusty Victorian idea, in contemporary London, with the super-rich and the marginalised world of immigrants and sex workers, the distinctions seem, if anything, more pronounced. The Slaughter Man moves from The Bishops Avenue in Hampstead, “where no expense had been spared and no taste exercised”, to a travellers’ camp off the A127.

Gruesomely, the meat market becomes a resonant symbol, too, in a novel which touches on both the sex trade and children as currency – a subject that has been of interest to the author since he was assigned to cover the work of London’s vice squad as a young reporter.

As a novelist, Parsons has always been good on a sense of place – from London to Phuket and Shanghai – but as a crime writer place is more than just a setting; it’s part of the thriller writer’s arsenal for drawing the reader in. Like the best of crime, from the LA noir of Raymond Chandler, the Nordic noir of Stieg Larsson and Henning Mankell, or the “Florida glare” of Elmore Leonard, The Slaughter Man is saturated in details. “You can’t go wrong with London because everything is here,” Parsons tells GQ. “From extreme wealth to extreme poverty, it’s The Naked City, 21st-century style.”

And while it might seem that the big-heartedness of Parsons’ earlier fiction has been replaced by something far tougher, that’s not the whole story. The choice of Scout for the name of Wolfe’s daughter is surely a tip of the hat to Harper Lee’s To Kill A Mockingbird, perhaps the greatest Southern crime novel of all time. Lee’s Scout is the daughter of the lawyer Atticus Finch who challenges his society’s racist prejudices. Max Wolfe might call travellers “gypsies” and imagine gruesome ends for the criminals he pursues, but is similarly energised by a sense of right and wrong. And crime fiction is ultimately about morality too. And with its big ideas and adroit plotting, The Slaughter Man’s position in the marketplace of fiction seems justly assured.