Stylistically unorthodox, a little mystical, with a big heart and a small page count, the novels of Max Porter (the prize-winning author of Grief Is the Thing With Feathers) are one of the surprise success stories of modern literary publishing. True, even his most ardent fans may have balked at the nigh-on impenetrable experiment of his last book, The Death of Francis Bacon, but admirers of 2019’s Lanny, Porter’s fabulist state-of-England satire about a precocious boy of the same name, are on safer ground with his new novel, Shy, about another eponymous boy who might be Lanny’s unluckier cousin. Shy, 15, lives at Last Chance, a rural institution for delinquent boys in the West Country, after being expelled from school (twice), cautioned at 13 and recently arrested. He has, among other things, “sprayed, snorted, smoked, sworn, stolen, cut, punched, run, jumped, crashed an Escort, smashed up a shop, trashed a house, broken a nose, stabbed his stepdad’s finger”. We join him when he’s creeping out of Last Chance in the small hours, heading to a pond with a rucksack full of drum’n’bass tapes and, more ominously, rocks. What follows, over 128 pages, is his jumble of night thoughts as Shy looks back on the turning points that brought him to where he is, as well as his interactions with staff and other boys at Last Chance. The narration unfolds as a kind of spectral swirl of voices in which assorted weights and sizes of type indicate different timelines. Vivid scenes erupt like lightning in fog, from Shy’s childhood anger at learning that Santa is actually his stepdad, to his slicing open another boy’s head with broken glass during a town-centre fracas in his teens. We’re in 1995, the dog days of Tory rule under John Major, whose words – “Society needs to condemn a little more and understand a little less” – Porter might have had pinned above his laptop to kick against. The result is exhilarating. One paragraph runs three-and-a-half pages without full stops to hustle us through the pile-up of bad luck and bad decisions that lead Shy to trash his school chemistry lab, having failed to lose his virginity after “fiddling around trying to get the smelly, greasy-thick condom on, useless knob like a dumpling”. Part of Porter’s point is that there’s more going on inside his protagonist than anyone sees. Listening to his jungle tapes, Shy hears the beat “crisp and juicy, mathematical perfection, up, up and away... Obviously he never says any of this... he just says Hardcore. Nice. Yeah.” But while the novel keeps in view the difficulty for those on the sharp end of Shy’s recklessness (his stepdad asks “when will the Jekyll and Hyde shit end”), there’s an unhelpful tendency to portray him as an ambassador for a superior moral universe. When a staff member asks what Shy worries about, he says the rainforests “and people slagging off Sting for giving a fuck... It winds me up.” It’s a problem, too, that Porter acutely catches the tensions and camaraderie of Shy’s combustible peer group without anyone else in it ever quite becoming a character rather than a counterpoint. It feels too convenient when Shy’s travails are put into context by reference to another boy, Benny, who grew up “getting pulled over for no reason” – he’s black – and whose father died in prison. One of the many voices bursting into the book says: “You are a stupid lucky bastard, Shy... Look at your crash net... Walk a mile in Benny’s shoes.” Despite the many brilliant scenes, and the sharp portrait of the cultural air Shy breathes (Tekken, Nicky Blackmarket, Jo Guest – basically a bag of madeleines for males of Porter’s vintage), the sense grows that the book amounts to an open-hearted exercise in style, reverse-engineered to show how society fails young men. Of course, it’s testament to the whirlwind prose that I only ever felt this way once I finally closed the book, left adrift by a warm but unearned finale that struck me as a too-neat signoff after all the pyrotechnics. Still – and however basic this might sound – I found myself wondering what would happen if Porter wrote a longer novel. Yes, he never outstays his welcome, a rare gift, but could he bring more to the party? Shy by Max Porter is published by Faber (£12.99). To support the Guardian and Observer order your copy at guardianbookshop.com. Delivery charges may apply