Bookish boy seeks moody girl, progressive parents optional. No hippy angst. If the debut main-stage play by D C Jackson was condensed to a lonely hearts ad, that's probably how this small-town rites of passage would come out, only funnier.

Jackson sets his comic cuts over one long, hot adolescent summer, at the centre of the universe that gives the play its title. For Barry, Michelle and Rab, they've reached that fleeting moment when everything's a matter of life and death, but is blissfully responsibility-free with it. Barry's smarty-pants wee sister, Norma, still has it all to come, bless her, because the gulf between being 14 and 16 is as big a deal as the two bus rides that make Barry and Michelle's three-day love story such a long-distance affair.

If all this sounds rather juvenile, it's probably the point. Because, while the lurch into more serious territory at the end of act one isn't entirely followed up by the second act's double-bluff of a plot twist straight out of Hollyoaks, Jackson has seen Skins as well. Consequently, he recognises that sweet tweeness by itself isn't enough. Rather, Gregory Thompson's increasingly confident production, in association with The Tron, drags Borderline into the 21st century. It remains wilfully charming, but is shot through with near throwaway insights into the magical possibilities of being young.

Scott Hoatson and Kirstin McLean are endearingly gawky as Barry and Michelle, Finn Den Hertog's Rab takes Julie Burchill's zero-tolerance line on anti-working-class language, and Sally Reid's motor-mouthed Norma is a delight. As growing pains go, The Wall looks like one more rite of passage Jackson has to deal with.