In hindsight, it was a strange choice for Valentine’s Day. One of Edward Albee’s later works, The Goat or, Who Is Sylvia? is a provocative play that asks audiences for a great deal of latitude as it goes about its deeper work exploring transgression and morality.

After last year’s success with Albee’s Who’s Afraid of Virginia Woolf?, State Theatre Company SA, partnering with Sydney Theatre Company, has leaned on the muscle of the American playwright’s reputation and Karvan’s star power to bring us this challenging dive into the murky waters between comedy and tragedy.

It’s Martin’s 50^th birthday and he is at the pinnacle of life. An award-winning architect embarking on the project of his career, with a gorgeous house and loving family – Martin (Nathan Page) is the epitome of white middle-class success. But it is all about to come crashing down.

The curtain rises on the lounge room of a stunning open-plan house, its modern lines tastefully decorated with mid-century furniture and abstract art. Martin’s wife, Stevie (Karvan), dances through the room arranging flowers. Married for 22 years, her contentment is seemingly undentable.

Then Stevie discovers the business card of a strange woman in Martin’s pocket. His jacket holds the scent of a weird perfume. “Is there another woman?” she asks with a smile. Yes, Sylvia. A goat. It’s too ludicrous. Stevie exits laughing, leaving Martin to make a more detailed confession to his best friend, Ross (Mark Saturno). This is more than lust. The word bestiality can’t encompass what he’s found with Sylvia. Martin is in love.

Like Stevie, the audience finds its first response in laughter. This is a step so far beyond social and moral boundaries it can only be countenanced with comedy. Laughter becomes a coping mechanism for the audience and a necessary device for the playwright – how else can such a grievous taboo be faced?

Yet, almost immediately, more transgressions are lobbed like grenades. Martin denigrates his 17-year old son Billy’s (Yazeed Daher) homosexuality as just a phase. Ross reminiscences about the two men paying for sex on a boys’ night decades ago while both were in relationships.

Nathan Page, Claudia Karvan and Yazeed Daher in The Goat or, Who is Sylvia? Photo: Matt Byrne

The flow of transgression is relentless, with the audience kept teetering between laughter and disgust. Is it only fear of public shaming that keeps our desires in check?

Albee’s signature rapid-fire dialogue grips the audience in a state of constant self-assessment, demanding each of us answer for ourselves where the line falls between the morally acceptable and the unforgivable.

One can only imagine the challenge State Theatre Company artistic director Mitchell Butel faced in choreographing the outlandish implosion of this marriage. Yet under his impressive direction, the performers are fearless. Given such an extreme emotional trajectory, Karvan rises to the challenge, sliding through the gamut of shock from laughter through disbelief to rage with moments of almost transcendent authenticity. Her monologues form the spine of the performance.

Page also hits his emotional marks as he attempts to explain the inexplicable, working himself into a notably snotty breakdown at the play’s climax. Saturno and Daher are strong in their respective roles, handling the swings between disgust and disbelief like old hands ­– especially impressive for Dahler, given this is his stage debut.

Strong performances: Nathan Page as Martin and Mark Saturno as Ross. Photo: Matt Byrne

Mention must be made of Jeremy Allen’s gorgeously detailed set – from its stark architectural lines to the choice of artwork and book titles, his design and attention to detail are extraordinary. Nigel Levings’ exceptional lighting, particularly the bluing of the tones as the play’s emotional register darkens, is a subtle yet flawless touch.

A man betrays his wife by falling in love with a goat. At heart, it’s ludicrous. But there is method behind this madness. Like Karvan’s Stevie, we are asked to contemplate a situation so outlandish it is beyond anything we might imagine; a relationship outside all social norms and moral conventions. What would we say? What would we do?

Albee uses the awkward zone between comedy and tragedy to push us beyond what is comfortable and acceptable, and to consider where we would each draw the line. What do we believe is ultimately unforgivable?

The Goat or, Who is Sylvia? is playing at Dunstan Playhouse, Adelaide Festival Centre until February 25.