Can one person change the world? Can a public act of self-inflicted agony convince others to think beyond themselves? Is life on a doomed planet better than no life at all? A young suburban mum thinks she has the answers in James Fritz’s Parliament Square—an explosive 90-minute play rattling Corpus Playroom this week.

Metal scaffolding encompasses the small stage alternately looking like a spider web or a prison. No other scenery adorns the space save the cast that sit on the periphery of the action, their faces blank and emotionless when not performing and yet watching each other’s every move. Claustrophobia is almost an understatement in this Bruntwood Prize-winning play; it’s more like a ticking time bomb that keeps the audience on edge from beginning to end.

Starting with the jolt of the morning alarm clock, lights come up on Kat (Becky Shepherdson) a seemingly happy wife and young mother arguing with what turns out to be her inner-voice played by the feisty Juliet Martin. The two bicker as Kat attempts to sneak away from her sleeping husband and embark on a journey to change the world and make Kat a household name by day’s end.

Despite the magnitude of the premise, the story remains surprisingly grounded as Kat alternates between fear, ambivalence, jubilation, hopelessness, and regret with her slightly braver and demanding inner-self by her side. While it takes a minute to accept the premise, Martin and Shepherdson swap dialogue with such ease and connection it feels as if they’re actually sharing thoughts.

It’s more like a ticking time bomb that keeps the audience on edge from beginning to end

When the scene changes and Martin disappears leaving Shepherdson utterly alone in the kind of isolation one only feels in room full people who don’t understand, the rest of the cast picks up the slack, handling particularly challenging material with grace. They drag Shepherdson back into the reality of her own life whether she wants to be there or not. Intimate family scenes offer a nice balance to the more cerebral first section but all are equally heart-wrenching.

Without giving too much away, I can warn you that Parliament Square is not for the light-hearted, nor is it particularly straightforward. At first the play manipulates time and space beautifully. As Kat and her inner-self make their odyssey, the two alternate between narrating the action around them and acting it out as they ago. Though slightly confusing, their emotional journey is so full the physical action matters little. However, what starts as poignant and thought-provoking in the first two acts falls apart in the third when Fritz attempts to cover 15 years of Kat’s life in about ten minutes.

It’s admirable to highlight how a single event can change a family over time. The ups and downs are moving but ultimately dizzying because it’s clear the actors – through no fault of their own – can hardly keep up. The two lighting designers (Chris Lazenbatt and Zak Karimjee) do an impeccable job creating what feels like a movie montage, but the scene would play better on film.

Director Kim Alexander also does her part to keep this complex play moving so the emotional intensity is never lost. There are a few moments in the beginning when props and space are sometimes real and sometimes not that could be cleaned up, but otherwise she does a brilliant job exploring difficult questions while managing vast material.

Ultimately, the play succeeds because the acting is solid all around. Despite the heavy subject matter, the ensemble never lets it veer towards melodrama. Annabel Bolton deserves a special mention for creating multiple distinct characters while infusing a bit of humour in an otherwise dark piece. Connor Rowlett and Charlotte Husnjak – as Kat’s husband and mother – also deserve credit for dealing with material well beyond their age.

However, this is Kat’s story and Shepherdson never lets her or the audience down. By bringing a level of honesty and vulnerability rarely seen on the student stage, Shepherdson embodies the complexity of the human spirt. She is unafraid to tackle what is terrible, shameful, and equally astounding and beautiful about life.

Though Parliament Square is purposely set in an ambiguous time and comments on unnamed events, it feels all too real and close home. Long after the play ended, I was left questioning my own global impact. Could I do better? Couldn’t we all?

Parliament Square is on at the Corpus Playroom until 19 May