Emma is alone, trapped and confused, unsure who to trust. From her bandaged wrists and her new doctor, we gather that she has suffered a psychotic break resulting from a terrible event. Her sister Alise has died in an accident – and without the release of the truth, she cannot escape her mind's torment.

While a musical about a girl trapped in a mental institution is a hard balance to strike, this performance does it very sympathetically. Written and composed by teenager Jessica Avellino and brought to the Fringe by US group Infinity Theatre, this is a deep and thoughtful look at teenage mental health.

We hear very little from Emma herself: she has been pushed into the background by the chaos and guilt in her mind. Fuelled by her secrecy, the chorus of voices from her mind load on criticism and questions, and ultimately keep her from telling her story. Some parts are perhaps a little naïve – a song about drugs barely touches the surface of side effects – but overall, the show is very thoughtfully done. The young cast perform very well and the backdrop of projections are darkly beautiful, perfectly suited to the piece as a whole.

I loved the contrast between the loud and vibrant songs from the hallucinations of Emma’s mind and the stark quietness of the institute, as she struggles to escape the lies in her head – so much closer and more real to her than reality. However, the staging held the show back at times: unamplified, it could be hard to understand what Emma and her doctor were saying in her room at the back of the stage, especially when other cast members were moving around.

I also felt the strangeness of the chorus being identically dressed is a little lost on a British audience. To us it appears a standard school uniform, rather than giving the intended, haunting effect of Emma seeing her guilt over her sister everywhere. It also makes the beginning somewhat awkward; I found myself trying to decide whether the costuming is part of the play or down to a shortage of dressing rooms.

And while much of the dance succeeds in conveying the feelings of the experience and the passing of time, some of the choreography is a little odd and out of place – giving the sense that the director felt the chorus should be doing something, rather than that the story necessarily needed them to be.

From the start, the show throws the viewer into a confusing world where the lines between imagination and reality are blurred; but there are tantalising hints of the truth that draw us in until we find answers. This surprisingly upbeat show is an empathetic look at what being trapped in your own mind can feel like. It provides food for thought, a terrifying glimpse into another world – and most of all, a hopeful message.