No matter what he writes, Stephen King will always be considered a horror novelist. It’s unavoidable now; he is responsible for too many of the fantastical nightmares that prowl popular culture. Yet in his latest novel, Billy Summers, there are no supernatural shades whatsoever (save a late Easter egg reference to a certain haunted hotel). Instead, he is in full noir mode, with a modest tale of an assassin on the requisite one-last-job-before-he’s-out. It meanders, it pays only the scantest regard to the rules of narrative structure, it indulges gladly in both casual stereotyping and naked political point-scoring. And it’s his best book in years. The set-up is straightforward. Billy is an ex-army sniper turned killer-for-hire who, conveniently for the purposes of readerly sympathy, only kills “bad men”. Tasked with a hit on a small-time crook, he relocates to a provincial city in an unspecified southern state where, due to the machinations of plot, he must live a double life in the local community while waiting for his shot. Like all good King protagonists, he fills his time with writing his life story. It’s a tale of violent youth and wartime tragedy that begins as an unwelcome interruption to the main proceedings but gradually accrues more weight as a window on to Billy’s off-kilter moral code. For 200 pages, Billy Summers feels like a retread of King’s alternative-history doorstop 11/22/63, told this time from the assassin’s perspective. Indeed, it’s easy to imagine that the genesis of the novel lies somewhere in King’s research into Lee Harvey Oswald. Like 11/22/63, the first half is pedestrian in pace but rich in colour and characterisation. King has always excelled at sketching everyman’s US, enriching the details into a minor epic register. It’s what elevates him above his genre peers, and it’s in full force here. Cook-outs with Billy’s neighbours, games of Monopoly with their children, date nights and diners – all are part of King’s mythologising of American life. Often this feels anachronistic – Billy’s tales of his childhood in a foster home sound more like the 1950s than the 90s, and a present-day visit to a fairground is barely different from a scene in The Dead Zone, way back in 1979. But King is not losing his touch. The book has plenty of references to contemporary TV and music, as well as allusions to changing demographics and progressive politics. (Not a single chance is missed to put the boot into Trump.) Any nostalgia in Billy Summers is intentional: it lulls us into a false sense of security. Knowing King’s penchant for the slow burn, it’s easy to imagine that the novel will build over 400 pages towards its climax in the sniper’s nest. Surprise, then, when we find that Billy’s time in the suburbs is the calm before the storm. At the midpoint, Billy Summers takes an entirely unexpected turn, introducing a character who will alter the course of Billy’s life and the nature of the novel. From here on the focus narrows, the pace quickens and the ethics become murkier. This strikes an odd balance with the sunlit, languorous first half. It shouldn’t work, but it does, largely because King is so good at character and making us care through incidental details. A little girl’s crayon drawing becomes a totem. The song “Teddy Bear’s Picnic” becomes a poignant refrain. By the inevitable, biblical climax, unlikely plot contrivances or dated sexual politics are forgiven, because we can’t help but be won over by the eternal figure of the lone individual making a stand. In interviews, King often references the American naturalism of Theodore Dreiser and Frank Norris, and the hardboiled crime fiction of Ross MacDonald and Donald E Westlake. Billy Summers combines these two strands into the author’s own brand of muscular, heightened realism. He may always be considered a horror novelist, but King is doing the best work of his later career when the ghosts are packed away and the monsters are all too human.