The Rehearsal is the most uncomfortable show ever made. Watch at your own risk

Amanda Whiting tries to work out if HBO’s new experimental comedy is the height of hilarity, or simply unbearable. Consider this your warning

Nathan Fielder in ‘The Rehearsal' (HBO)

Some shows never leave you. There’s a devious moment toward the end of the premiere episode of The Rehearsal – HBO’s slippery new experimental comedy from earnest Canadian Nathan Fielder – that’s as much a part of me now as anything else I’ve ever seen on TV.

Fielder sits down with one of the show’s real-life participants, an easy-going 50-year-old Black man named Kor Skeet, and confesses to lying about something trivial – his timorous delivery is comedy’s answer to mumblecore. But when the camera cuts to Skeet, the trivia-enthusiast has been replaced by an actor who looks a good deal like him. The actor delivers a brutal dressing down, and Fielder sheepishly takes it.

In the following shot, Skeet is Skeet again, warm if a little quiet. The temporary recasting is never acknowledged. Maybe it never even happened?

It’s tricky to describe The Rehearsal, Fielder’s wickedly ambitious follow-up to his 2013 word of mouth hit Nathan For You. It’s tricky to describe because I don’t want to spoil a single disturbing morsel of it, and because there’s nothing else out there remotely like it. As on Fielder’s Comedy Central docu-series, the cast is mostly made up of non-actors. The comedian finds people on the precipice of a hard choice – from confessing an old secret to deciding to have kids – and sets up a meticulously detailed, life-size “rehearsal” space so that they can practise, over and over again.

If this doesn’t sound funny to you, that’s because it’s largely not. It’s awkward, uncomfortable, and excruciating. But the concept is kind: human beings improve at things the more we do them, and Fielder wants to turn people into experts at their own conundrums. In a way, The Rehearsal is an antidote to the hidden-camera comedies you’ve watched before, the ones –  including Nathan For You, which saw Fielder pitch inane schemes to small business owners – that trade in pranks and embarrassment.

Still, The Rehearsal, always hovering on the uneasy knife-edge of exploitative, is upsetting viewing. In episode one, Fielder proposes to help Skeet confess to a trivia teammate that he’s embellished his CV – a secret so exquisitely banal that just the idea of “rehearsing” it will have you giggling. The master of controlled chaos even builds a replica of the bar where it’s all meant to go down.

But Fielder, it follows, has his own sticky situation to rehearse: he’s never asked anyone to come on this zany show before. So prior to meeting Skeet, he sends in a team of “technicians” from a fake utility company to spy on Skeet’s house. He builds a replica of Skeet’s apartment and hires an actor to study videos of Skeet and improvise in character. In a clever recursion of the show’s set-up, Fielder reveals that he’s rehearsed every aspect, from the throat-clearing banter as he walks in the door to the eventual confession that he’s already spied on the poor guy he wants to help. Yes, Fielder’s running this social experiment, but he’s also its most eager subject.

Part of what’s uncomfortable about watching the show is that Fielder himself appears uncomfortable making it.

As a comedian, Fielder thrills to take a simple idea to its comic extreme. The “decision tree” he makes for the night of Skeet’s big reveal is so crowded with choice, arrows, and possible outcomes, that it’s mostly a visual gag. Always creeping uncomfortably around the corner is the fact that Fielder’s no Oprah Winfrey, or even a Dr Phil. Once a participant accomplishes their goal, as Skeet more or less does, there’s still the matter of running it all back on TV, where even Skeet will see the spoofy flow-chart.

Yet part of what makes watching The Rehearsal so uncomfortable is how routinely you need to remind yourself that this isn’t altruism, or even a real self-help show. The act of rooting for a down on his luck television character like Skeet is so seductive that the marionette strings connecting Skeet to Fielder’s control bar threaten to go invisible.

Nathan Fielder behind the controls of ‘The Rehearsal’ (HBO)

Which is why that final moment – the one in which Fielder replaces Skeet with a hired doppelganger – is so destabilising. When the credits rolled, I replayed the scene just to be sure it really happened. Fielder wants you to keep seeing the strings. He wants someone to call him an “awful, awful person” on TV. He knows he’s tricking people and part of what’s uncomfortable about watching the show is that Fielder himself appears uncomfortable making it.

Except he’s not really uncomfortable with it, is he? Fielder orchestrated The Rehearsal, filmed it, and put it on television for the rest of us to laugh at. Perhaps the real experiment lies at the limits of self-awareness, which the comedian seems to possess in unbearable droves – or maybe not at all. Because you can’t apologise in advance for the “awful, awful” thing you’re about to do, not in any meaningful sense. And just because the mad scientist is willing to hook himself up to his own monstrous creation doesn’t make it any easier to watch.