Just over a year ago, Caeli Colgan and Aaron Gelkoff lit up the Burton Taylor Studio in Oisin Byrne's meta-comedy about acting, Unprofessional. Now they're back (along with Rohan Joshi on one of his rare sorties beyond the walls of St John's College) to scratch that itch again.

David Ireland's daring, outrageous play is a real-time pressure-cooker with no 'off' button. It's about a famous American actor (Gelkoff), a celebrated English theatre director (Joshi) and the Ulster-based writer of the play they're about to start rehearsing (Colgan) meeting up to discuss the show. At least that's how it starts. By the end it looks like the aftermath of a Quentin Tarantino movie. Tarantino is frequently mentioned with viciously tongue-in-cheek reverence in the script. But where his violence is borne of a need to shock, Ireland's comes from somewhere deeper: a need to break out of the hypocrisy of performative language that acts as both armour and disguise in our supposedly enlightened society.

I don't think I've ever felt such an exquisitely painful combination of discomfort and hilarity in the theatre. With almost every speech, the two men compete to declare their woke credentials, while laying obliviously bare the prejudice and deception lurking about a millimetre below the surface. This is dramatic irony in a tiny room but a grand scale.

Gelkoff is every inch the self-absorbed, preening actor, trumpeting his new man credo ('I love women: my agent's a woman - a black one') and tying himself in knots of political correctness. Not only can he not say the N-word, he claims, but he can't even say the words 'the N-word'. Gelkoff's comic timing is a wonder to behold, and his rendition of an American just about failing to do a Belfast accent is simply glorious. As Ruth (Colgan) says, he's Dick van Derry.

Joshi meanwhile starts out sympathetic, calm, the perfect star-wrangler. It's only as things start to slide out of his control that his true motivations and manipulations unravel before our, and his own horrified, eyes.

And Colgan, as the writer Ruth, is a beacon of accusation. Her no-nonsense, honest rationality dismantles the men's posturing, even though her inability to compromise leads to her own personal tragedy.

Taken together, these performances are about as remarkable as any you could see from a group of actors, professional or student. They mine every nuance of Ireland's delicious, acerbic script, and bring it to a point where language has no meaning, and only violence remains.

Directors Kate Burke and Robyn Hayward clearly know how to get the best out of their superb cast. They gently nudge the action up the scale from sedentary calm to attempted murder, with the BT stage unusually surrounded by audience on three sides, intensifying the crushing tension of the play. As well as general laughter, there are lots of individual outbursts from the audience: pained squeaks of hilarity like involuntary verbal farts brought about by the combination of outrage and comic unease.

Ulster American is very much a play for today. In a world of content warnings and cancellation fear, the ugly face of true human nature doesn't often show its grisly, clownish visage. It's dark, dirty, rapacious and cruel. Its message is bleak and cynical. But sometimes we need to see it. I suggest you do - if you can get a ticket.