Nodding enthusiastically, a pyjama-clad Boy invites us to join a game of ‘it’ in a curio-filled theatre space under the dark arches of London Bridge.

This is our introduction to Belt Up Theatre’s latest show at the Southwark Playhouse, a three-hander loosely inspired by moments in JM Barrie’s Peter Pan and from the Scottish author’s own life. While Barrie’s native accent is deployed by James Wilkes as a suited, haggard-looking James as well as Jethro Compton as The Boy, the Peter Pan source is not explicit. It’s unlikely this will prove a bar to enjoying the show though, which explores some hefty, dark thematic territory after a typically energetic kick-off to proceedings.

James is trying to throw off his childhood self, but The Boy won’t stand for that, pleading for another adventure together. When James is knocked out of action by The Girl (Lucy Farrett), events take a nastier turn.

She demands The Boy kiss her, “like this”, demonstrating on James' prone body, before chasing the (by now terrified) Boy around the room, climaxing in a harrowing sequence reminiscent of Wedekind’s Spring Awakening.

Belt Up have a knack for conjuring moments where hand flies to mouth in shock, leaving the audience feeling uncomfortably similar to bystanders at a late night brawl, and Dominic J Allen’s direction is on good form, despite one too many drops in pace. Writer Alexander Wright proves a budding raconteur with his script for The Boy James; let’s hope it reminds all of us not to grow up too fast.

- Vicky Ellis