If you’re driven mad looking for “the session” at Edinburgh, then look no further than Dublin Oldschool at the Pleasance Courtyard. This is a whopper – a verbally explosive, express-train of a play that will break your heart even as you’re laughing. We all start decaying after 21, so how many more years of “the craic” have we got left? Do we stop at 33 and die like Christ did?

Jason is a man “with six cans and a plan.” A wannabee DJ, we join him on a three-day bender though Dublin’s scummy club scene. He keeps bumping into his brother Daniel, a homeless heroin addict who’s just returned from London after a few years away.  Although Jason can’t understand how his brother graduated from “yokes” to stronger “gear” so quickly, it’s clear his own penchant for the stuff is gradually destroying him. As he desperately tries not to think of his ex-girlfriend, Jason clings to the hope of being the support act to a famous visiting DJ.

There are a lot of familiar ideas here but nothing feels tired. Emmet Kirwan has written a rich, high-energy and verbally dextrous script. Language seems to fall in on itself in beautiful shifts of rhyme and rhythm that are constantly surprising.

Even rare moments of cheese and almost teenage cringe can’t detract from this play. In fact, these moments of adolescent temperament are necessary. Irwin has achieved something like lighting in a bottle. It’s not all about cherishing what youth we have left or regretting what’s lost. Here, youth is cyclical. We imagine “a younger version of ourselves in a far distant future.”

Kirwin also performs in this play and is joined by Ian Lloyd Anderson as Daniel. Both actors deliver accomplished and physically impressive performances. Director Philip McMahon has charged every second of this play and, unlike a lot of new writing at the fringe, there are no spare parts. If you’re looking for something special to catch in the last few days of the festival, then this show is not to be missed. Although, you might have a hard time trying to find a ticket.

Dublin Oldschool is playing at the Pleasance Courtyard until August 28.