There is a delicious sense of Groundhog Day at the re-emergence on stage of Dave, Pete, Humper and Alison, the central characters of Gary Mitchell's pulsating 1999 play Energy. But that sensation is far from delicious for the quartet themselves, for whom, to put it mildly, life has not been kind.

Mitchell's keenly anticipated sequel Re-Energize fast-forwards the action 30 years, building on the affection and nostalgia generated by its forerunner and catching up with the four members of a has-been band, now struggling to keep their heads above water in the changing times of the so-called 'new Northern Ireland'. What remains undiminished at the core of their derelict existences is their devotion to punk music and to their unfulfilled, covert aspirations to get out there and prove it can still speak powerfully to and for the people.

In a recent article for Culture Northern Ireland, classical composer and musician Dr. Philip Hammond mused on what could possibly have been judged interesting about punk's "...limited harmonies, these vocal monstrosities, these undistinguished and indistinguishable lyrics?" He is answered by writer Glenn Patterson, who explains that none of that actually mattered to the fans, who only wanted "...to bash out something to express what they felt or wanted to feel or could identify with. Educated finesse wasn’t part of their language - it was raw emotion, rough energy, unfettered by convention and responsive only to the immediate."

And this scenario most definitely remains the case with these four downtrodden, world weary individuals. Middle age and hard times may have fallen upon them, but Conall Morrison's urgent, relentless direction lights a flame under that same spirit of raw, unfettered energy. Meanwhile, the enthusiasm of a new generation of followers, here personified by Alison and Humper's respective offspring, is ignited by a tremendous set of songs by John and Damian O'Neill, whose Undertones credentials make them the perfect collaborative partners.

Sabine Dargent's set catapults us back into the familiar, rancid surroundings of the band's rehearsal room. In the intervening years, nothing seems to have changed - pizza boxes, beer cans, takeaway cartons and clothes litter the floor, the egg-box sound proofing remains half-finished - and amongst it all sprawls Michael Liebmann's disastrous Pete, a little paunchy these days, but intent on cultivating his image as the oldest swinger in town while nursing yet another monumental hangover. Times have changed though. The location is now the garage of a pensioner's bungalow - or bachelor pad, as Pete insists - the home he shares with Dave and whose rent is paid by their collective disability living allowances.

Chris Corrigan's perpetually anxious Dave has become quite the homemaker, bustling about in a pinny, cooking roast dinners and acting as surrogate part-time parent to his brother Humper's surprisingly well brought-up teenage son Benji (a sweet performance by newcomer Gavin Peden). But, on a day-to-day basis, these ageing bass and rhythm guitarists can't escape either the pull of the music or their pathetic desire to prove that, given the breaks and in other circumstances, they might have made it into the big time - and, actually, still could.

If he thinks about it at all, Andy Moore's good-looking but doomed Humper is more realistic about their prospects - or lack of prospects. Like Alison, played with honest-to-goodness, down-to-earth realism by Jo Donnelly, the trials of parenthood have given him a different perspective. While he, for unlikely reasons revealed by Dave to Benji, has largely opted out of the lad's upbringing, Alison has battled single-handedly to keep down a thankless job in order to support herself and Niomi Liberante's lippy, smart-assed AJ, the archetypal adolescent who thinks her mother is hell bent on ruining her life.

As though unemployment, straitened finances and poor health were not enough to contend with, the lid is lifted on other realities of life in inner-city Belfast in 2013. Mitchell cranks up the tension several notches through the arrival on the scene of James Doran's deceptively affable Young Cecil, who has taken over the family business from his more user-friendly father Old Cecil. This smiling, sinister character symbolises some of the issues to which socially deprived communities in the North are exposed in the current political and economic climate. Raised on the hardline loyalist Rathcoole estate, Mitchell does not flinch from exposing the hideous activities of the loan sharks, racketeers, pimps and traffickers who prey on vulnerable people.

The seven actors deliver unanimously sound individual performances, as well as combining successfully as a musical ensemble. They exude a palpable sense of pleasure at being on stage together, particularly in the case of Moore and Corrigan, who made their first professional appearances in Energy at this same venue fourteen years ago. Donnelly morphs with effortless ease from dowdy, beleaguered mum to snarling, manic lead singer, eyeballing the audience with all the attitude of punk at its rude best. And different though their characters may be in personality and outlook, Peden and Liberante are symbols of a generation of Northern Ireland kids who have no memory, little consciousness and total disregard for the Troubles and are far more interested in skipping school to play music or maintaining a hectic social media life.

Mitchell and Morrison are old sparring partners, who, back in the 1990s, worked together on two of the former's finest plays - In a Little World of Our Own and As the Beast Sleeps. Their creative partnership has resurfaced effectively here. After an extended period in the twilight zone, during which he suffered intidimation of the most terrifying kind, Re-Energize sees a resounding return to form for Mitchell. While there remain one or two expositionary scenes which could benefit from additional pruning and tightening, on the whole the script is taut, tense and intelligent.

Ultimately, though, it is the music which provides a lifeline, a salvation, an alternative lifestyle, a last chance. The final ten minutes is wall-to-wall sound. Played and sung live, with the volume cranked up to the max, it sounds, well, magic.

Jane Coyle is a Belfast-based freelance arts journalist and critic, who also contributes to The Irish Times, The Stage, Culture Northern Ireland and BBC Radio Ulster.