Irvine Welsh’s 1993 debut novel Train-spotting flicked a hearty V-sign in the face of alarm-clock Britain. ‘Ah choose no tae choose life,’ crows its giro-cheating antihero Mark Renton, proudly enslaved to heroin instead of mortgage repayments. But when Welsh revisited his native Leith for a 2012 prequel, Skagboys, he threw over this bourgeois-taunting amorality for blunter politics: Renton, it transpired, first turned to heroin for pain relief after police beat him up on a picket line during the 1984 miners’ strike.

In Welsh’s latest novel, it’s the turn of Renton’s psychopathically violent frenemy, Francis Begbie, to get an origin story involving the abuse of state power. As a boy (we now see) Begbie struggled with dyslexia. The regular chorus of classroom laughter was led by his ‘bullish, rugby-playing’ teacher, Hetherington, ‘leather elbow patches on his checked jacket [Tories, eh?]…. I raged inside’, Begbie recalls. ‘I learned that letting that rage out was the way to stop the laughter: to stop it by turning it into blood and tears.’

Anyone who finds that hard to swallow may struggle with The Blade Artist’s central premise. Begbie, now in his fifties, several jail terms down the line, has anger-managed himself out of Scotland and into a new life, under the name Jim Francis, in California. A successful sculptor (his grotesquely mutilated busts of film stars are hailed as satirical embodiments of the vengeful envy driving celebrity culture), he spends his downtime at the beach with his two young daughters and his wife, an American art therapist who turns out to have been on placement at the prison where Begbie was banged up in Porno, the 2010 sequel to Trainspotting.

Ever since Trainspotting — made up of discrete episodes held together by a strong narrative voice — Welsh has leant on crime plots to structure his novels. The spark here comes from the fatal stabbing of Begbie’s 21-year-old son Sean, the product of wild oats sown and long forgotten. Making a rare return to Edinburgh for the funeral, Begbie finds his former gangland rivals suspiciously keen to blame the unsolved murder on a young drug dealer who owes his position as top dog in the city’s trade to a flair for settling beefs by means of drive-by assassination rather than the traditional brawl.

If you feel Welsh might have been spending some quality time with box sets of The Wire, the action is generally more Hollywood than HBO, advancing thanks to information aired during increasingly sadistic torture scenes. But this being Welsh, there’s plenty of funny business too, with Begbie’s new Santa Barbara palate — he has to get that egg-white omelette — always good for a laugh. There’s also a great deal of rabble-rousing:

Funny how a prime minister can condemn a whole generation ay bairns tae a future ay poverty, or gie the order tae wipe out Iraqi women and children in a phoney war, and they cunts get described as great men ay history… The likes ay you or me, we take oot a few radges that naebody misses, just fuckin pests tae their ain community, and we’re the big villains!

Yet if Begbie’s Jekyll-and-Hyde-like regression sees him pulp a fair few bad guys — a rapist and a paedophile among them — the search for answers about Sean ultimately entails a stern look in the mirror: it’s clear that Begbie hasn’t exactly earned that sanctimony about women and children. And doubts linger about his crime-fighting skills — a rock to the back of the skull; a sly knitting needle in the guts. Dyslexic or not, Begbie was always vicious, not hard. Wouldn’t tell him to his face though.