Tim Edge’s debut play is a thriller set in Belfast at the height of the Troubles; plotting one family’s demise as father, son and, finally, daughter are drawn into a cycle of violence that appears both inescapable and enduring - much like the titular black rock that hangs above the stage for the course of the show.

Evanna Lynch - best known for her role as Luna Lovegood in the Harry Potter series - stars as the daughter of Cashel Ryan, an imposing patriarch and member of a republican cell that commits acts of terror and punishes traitors. Edge is deliberately sparing in his description of the wider political context of the time; eschewing a historical explanation in favour of something that aims to examine the human cost of the 30 year struggle.

The issue is that too many characters and a plot-heavy, choppy script means we’re never given the chance to find our footing in this complex, often confusing world of ever-shifting loyalties. Despite the high stakes, it’s hard to get a grip on what it all means for the characters, nor what they mean to each other. We jump from scene to scene as actors rattle through their lines and switch between different roles. Dramatic lighting and a striking soundscape escalate the tension - achieving some cinematic flourishes - but without enough investment in the characters it fails to resonate more deeply.

Despite these flaws, some strong performances keep the audience engaged. Keith Dunphy is endlessly watchable as the charismatic, compromised Catholic priest, Father Paul Flynn. And youngest cast member Jordan Walker shines as neurotic bomb-maker, Fin; calculating how best to cause maximum loss of life with terrifying zeal.

The director, Ben Kavanagh, refers to the collaborative process the script has been through; with himself and the cast reshaping Edge’s original ‘seed play’ into ‘the magnificent epic oak’ that we see before us today. While this approach is commendable, one can’t help but wonder if somewhere along the way the tree outgrew its roots and, a bit like that hanging black rock, became the rather unwieldy, inscrutable production that we are left with.