Three hours, three plays, three venues, three lost souls. They'll be in their fifties now, the 18-year-olds in this devastating trilogy from 1977, and so immediate is Bill Buckhurst's revival of Barrie Keeffe's howl into the wind that you can't help wondering what became of them if and when they grew up.

After years of neglect, two new stagings of Barbarians are reaching London this autumn alone. In the current political landscape their pertinence is an indictment, and a timely reminder, of the little our society cares for its disenfranchised youth. The Young Vic will be presenting it in November, but first comes this revised transfer by Tooting Arts Club (in association with Soho Theatre) of their 2012 production. Performed over a couple of floors in the derelict former home of Central Saint Martins, it leaves you punchdrunk.

Loutish Paul (Thomas Coombes) flounders in the shit of life and rages against his inability to climb out of it. "There's always a fucking wall in the way. Always get so far, and there's a wall to block it. Smash it down, smash it down". Louis (Josh Williams) has a bit of training under his belt that's given him a shred of pride but little hope of a career, while Jan (Jake Davies), the youngest, doesn't know what he wants but it has to be better than this. Deep down all three of them yearn to conform and to find their place in society, but they don't know where to begin. So they turn to aggression.

Keeffe's compassion for these young men infuses every moment of the plays, even when their behaviour turns caustic, and that's an essence that Buckhurst brings tellingly to the surface. On Cup Final day they strut like peacocks, but underneath the tribal plumage they're scrawny, soft-skinned and vulnerable. And their naive bravado triggers a vein of comedy that's never entirely comfortable; indeed, so profoundly do we learn to care about the boys that the dark finale, when it arrives, is shattering.

All three actors are personable and full of character; however Coombes, the only survivor of that 2012 company, is the most remarkable of them. Paul is potentially a one-note creation but he grips the attention: angry, pathetic, desperate and, when it counts, truly terrifying. Williams captures the intelligence and confusion of Louis, an inherently good person whose lack of opportunity lands him in thrall to Paul, while Davies contributes a buzz of late childhood as Jan, a bit like Paul Whitehouse's Lance at times but the quiet master of the trilogy's final play.

Inevitably, some aspects of Keeffe's dramas have aged better than others - unsympathetic references to the British Army in Belfast grate today, in an era when we are more likely to castigate parliamentary leaders than the soldiers who do their bidding - yet its power remains extraordinary and its message depressingly relevant.

Barbarians runs at the Central St Martins School of Art until 7 November.