Community theatre group Our Space makes great use of the pop-up theatre at Plymouth's T2, packing the auditorium for an intense treatise on mental illness.

And on a sultry summer evening with pre-performance drinks and gatherings out on the water's edge, there's a real feelgood factor about the place.

The Edge, A Theatre Royal Plymouth Our Space Production
The Edge, A Theatre Royal Plymouth Our Space Production
Director Lee Hart springboards from a chance retelling of Gabriel Garcia Marquez's short story I Only Came to Use the Phone to create The Edge in conjunction with the company, some of whom have close experience of the subject matter.

This is a simple nightmarish tale, set in pre-mobile phone days, of Maria who breaks down near a mental hospital and is admitted.

Her sanity is methodically destroyed in the tedious round of institutionalisation and abuse where it is impossible to buck the system.

Clare Cox is superbly vulnerable as Maria although I would like to have witnessed a more strident voice initially. In particular her intimate moment with the hat stand was beautifully portrayed. The nurses Rita Carlton, Sue Hurst and Sam Saggers are believably regimented and authoritative, on duty from the very start, while the company are consistent with their tics and compulsions adding claustrophobic padding to Maria's breakdown.

Tony Kelly convinces as frustrated husband although I would have liked there to have been less certainty for longer as to whether Maria had been admitted or accidentally entered a living nightmare. The Theatre Royal Voices, ephemeral onlookers behind a gauzy screen, add dimension - but Ave Maria does seem an odd choice – while the excellent use of the medical screen for silhouette action and projections is particularly noteable.

- Karen Bussell