Sophie Okonedo and Toni Collette in Wanderlust

‘This is when? Where are we now?’ – so says Joy’s therapist in the penultimate episode of Nick Payne’s excellent polyamorous rom-com. And it suits its tone perfectly.

Opening without a title sequence, we are plunged into a mirage-like summary of all the bad that’s happened to Joy so far – most significantly her husband’s description of his love for another woman, revealed in full last week. She is now splintered, devastated. And the tears don’t stop running there.

Episode 5 takes place mostly in a curtained-off therapy room with Joy (Toni Collette) and her therapist Angela (Sophie Okonedo), getting to the root of Joy’s problems. We swirl from memory to memory, splattered with sadness, with such confusing speed that the therapist’s question at the start feels like an understatement. The common centre, however, is attending her mother’s funeral as a teenager.

This process is intensely baffling at first, like throwing up a jumble of disorganised laundry in the air with no discernible direction – but how could it be anything else? Under such emotional stress, logic and order are difficult to sustain. Yet this is exactly what Joy tries to do. Throughout the 55 minutes, a line from her father is returned to again and again (said before her mother’s funeral): ‘Don’t make a fuss, Joy.’ It’s like she’s never stopped hearing it.

Payne executes this with such heartbreaking emotional force that it’s hard not to cry within the first 15 minutes. It’s like Toni Collette absorbs the camera, washing it around her mind, reconstructing her past to understand her present and consider her future. And with the Einaudi-like score from composer Peter Broderick, we really didn’t stand a chance.

Episode 5 is like a poignant ultimatum – the result of this session will determine what Joy does next, and what she’ll do for the rest of her life. We thought Wanderlust was a break for Toni Collette, who already demonstrated her emotional range in Hereditary, but we were so wrong.

This isn’t, by any means, the conversational comedy we’ve adjusted to. It’s something more, and Payne has burrowed the drama under four episodes before finally exploding in the fifth. Maybe the sixth will be even more impactful.