In twenty years the relationship between Katherine (Athena Stevens) and Harrison (Tim Beckmann) is planned, realised and eventually demolished. Not unlike the buildings that Harrison has always wanted to design and Katherine ends up creating, the life cycle of the relationship has an end point. Whilst one member of this couple sees a critical design flaw, the other sees potential to develop and grow. “How can you help a woman whose own body assaults her dreams?”

Harrison sees a problem, the ultimate road-block for Katherine. He sees her in a wheelchair at 14 and realises that her cerebral palsy will eventually prevent her from achieving her goals. How can you be an architect and design stairs that you can never climb? But she breaks into his house at the start of the play for help, for guidance and for a chance to prove herself. Katherine doesn’t see obstacles – she sees ways to prove people wrong. As a typically arrogant, know-it-all teenager, she comes to him looking for support and for inspiration. Together they find love in a mutually beneficial symbiosis. But ultimately the struts that hold up their relationship buckle and bend – Harrison needs Katherine to depend on him and his role as her carer masks his insecurity around their first meeting as teacher and ex-student. A closer look reveals the fundamental error in their foundations, as Katherine becomes all that Harrison couldn’t. Despite her personal difficulties, she has the independence and the strength of character that he lacks.

As the writer-actor of Schism, Stevens has a unique insight into both characters. She seems to pour real life experience into the story yet not make the play one-dimensionally centred on her disability. Her character’s dependence on her partner may be physical, but his dependence is emotional and this exists regardless of whether she is in a wheelchair or not. As the play progresses, Stevens has the capability to grow with her character. Playing an accelerated timeline is difficult; there needs to be so much development in such a short space of time and Stevens delivers this with aplomb. As the emotionally crippled counterpart, Beckmann is also a strong performer; he conjures up a teacher-like position of assurance and responsibility when needed, but always exposing the cracks in his character that break the façade. There is a well-established internal conflict that comes across convincingly, as Beckmann sees his student-turned-lover achieve the dreams he always aspired for. In the end, as she returns a stranger, he looks out the window at Alex Marker’s blueprint backdrop and is a broken man. Alex Sims’s direction draws out the parallels between the architectural aspiration and the crumbling relationship to good effect.

From the start of the play, the title gives the game away. Schism shows that divisions can dealt with in very different ways – we can fall down into the resulting chasm or we can construct a bridge, cross to the other side and keep going with our journey.

Schism is playing at the Finborough Theatre until 14 May. For more information and future shows, see the Finborough Theatre website.