At a remote stop, a homeless man gets on a bus without the fare and the driver won’t move until he pays. The delay stretches on, and tensions among the passengers rise as they take different stances as to whether or not to throw him off the bus. It is a fascinating premise: an opportunity to raise questions of morality around kindness and responsibility, the rule of law, and the rights of the many versus the few. The bus is a microcosm in which the way society functions for the benefit of the many while looking after the vulnerable can be explored.

As an ensemble piece, Glass House relies on its strong cast. Playing the homeless man at the centre of the drama, Rafael Griso as Eden has an outsider intensity that allows an ambiguity of helplessness and danger. May Daws as Freya is particularly convincing, sympathetic yet wary, sharp enough to stand up for herself but not strong enough to force the issue. The interactions between the characters are believable, though the tension erupts into aggression far too quickly, but the dialogue fizzes at times, as the characters make alliances, snap at each other and tell some home truths.

Yet despite some lovely performances and excellent vignettes, the play has too many flaws to really succeed. The key initial plot point of a driver refusing to allow anyone else to pay for the homeless man seems inconceivable – and the character most opposed to his remaining on the bus is so deeply unpleasant, any points she makes about personal responsibility are lost. It is not clear what the framing device of voiceovers of the passengers being interviewed about events later adds, except to clarify the changing feelings of a key character which seemed unconvincing during the action on the bus.

This is a play with much potential, though, and some alterations to the mechanics of the plot could elevate it to an intriguing piece of theatre.