Noni Hazlehurst and Andrew McFarlane in The Heretic (Pic: Jeff Busby)

Despite the flurry of publicity around the opening, Melbourne Theatre Company’s The Heretic is not actually about climate change. The debate just provides the set-up for a peculiarly domestic comedy.

The first act of British writer Richard Bean’s play is a tough slog for the audience. Scientist Dr Diane Cassell (Noni Hazlehurst) has found some sea-level data that doesn’t fit the model of anthropogenic global warming. Disobeying the orders of her department head, Professor Kevin Maloney (Andrew McFarlane), Cassell publishes her paper and staunchly defends her right to stand by her empirical results.

The audience are then treated to a one-sided debate, where Dr Cassell, with all the best lines, rebuts the arguments of those around her. These include Professor Maloney, her daughter (Anna Samson), a student (Shaun Goss) and even a campus security officer (Lyall Brooks). These supporting characters, representing various shades on the green end of the political spectrum, are written as confused dunderheads. In director Matt Scholten’s production, they are played so broadly for laughs it becomes truly perplexing. It’s as if they have wandered in from a British bedroom farce; they’re all stock characters being setup for a fall.

The laughs are no doubt dramatically necessary to save the play from being purely didactic, but the supporting characters all pitch their particular crazy eccentricities so high, there’s nowhere for them to go.

Only Hazlehurst plays it straight and with the writing skewed so far in her favour, any real scientific argument becomes pretty irrelevant. No matter where you stand on man-made climate change, there’s little here to challenge your preconceptions.

Thankfully, Bean virtually drops all pretence of scientific debate after interval. With Dr Cassell no longer working at the university, the second act takes place at her home and it becomes clear that the heart of the play is actually a domestic comedy.

The playwright ambitiously then takes the dramatic style in multiple directions. Weaving between intergenerational comedy and out-and-out farce, the play adds in elements of the thriller and the family melodrama. These elements are interestingly layered on top of each other, so we have the conventions of the different genres playing out simultaneously. It’s a daring gambit that this production isn’t nimble enough to pull off, but it certainly makes the second act more dramatically interesting.

All debate on climate change is shelved as the supporting characters soften from into more recognisable humans. Samson, in particular, is able to invest a sharp anger into her character so the key mother-daughter relationship at the centre of the play shines through.

The Heretic is ultimately a confused play, formally skittish, that requires a firm hand to keep it from falling into the traps of didacticism on one side and broad farce on the other. It doesn’t quite stay on track but it’s a fun and bumpy ride once the global warming mock-debate is done.

The details: The Heretic plays the Sumner Theatre until June 23. Tickets on the company website.