Inside No. 9 is, rightly, lauded by critics and fans alike. The series takes a dip into a different genre each week, and the results are generally ingenious and satisfying. Some episodes are misses, but that’s a casualty of the anthology style – and it means that next week is always a chance for something new. It’s always a joy knowing that there’s a new IN9 coming each week.

But it’s possible that IN9’s tightrope position – niche, but not too niche, with both a cult following and multiple awards – has landed it in a sticky situation, review-wise.

Because I can’t for the life of me figure out how this episode has achieved uniformly positive – not even positive, glowing – reviews. Even accounting for taste, I don’t think this episode deserves anything near that.

A bizarre mash-up of heist film and Renaissance Italian play, the episode does nothing interesting with either of those concepts. Indeed, it fails to even fulfil even the basic expectations of the heist genre. Every good heist film has a high-stakes and clever climax; either a seemingly impossible problem solved through an earlier set-up, or a flashback revealing what really happened. The clever heist twist of this episode centred around a fake bag of diamonds being exchanged for the real one. To pick a random example, even the (rather good) Solo: A Star Wars Story managed a similar climax in a more entertaining way, sewing constant doubt over whether the coaxium shipment was real or not. Like any heist film, our expectations were subverted and twisted this way and that, keeping us engaged – and guessing – until the final reveal. In this episode, we saw the diamonds swapped early on, and nothing more complex happened than that.

Of course, the heist wasn’t the only genre at play here. The episode was also a mixture of commedia dell’arte, which I more or less interpreted as Shakespearean comedic farce – a genre the series did fantastically well, and far better, in Zanzibar. Again, the building blocks of this genre were simply there. The episode did, of course, acknowledge that the only connection between the two was the use of masks – but hanging a lampshade on something doesn’t automatically solve the problem. Perhaps there’s a reason that masks are the only thing they have in common.

I also found the metatextual elements of the episode – the third genre, I suppose – bizarre in the extreme. Neither a feature of heist films or (Wikipedia tells me) commedia dell’arte, it was instead thrown in for the hell of it. Cheeky asides to the camera are one thing – and the Miranda joke was the best of the episode – but references to reading ahead in the script came to nothing. I would have expected these references to be paid off by, for example, a character merely pretending to die because she’d read ahead in the script and discovered that she was going to be killed – or by the episode ending with the reveal that the entire thing was in the process of being written by Pemberton and Shearsmith. Any sort of pay-off to any of these three disparate genres would have been appreciated – let alone a clever one that combined the three, which is a resolution I’d expect from this exceedingly talented creative duo.

Instead, the three ingredients of heist film, commedia dell’arte and metatextual commentary sat in the pot, unblended. While somewhat entertaining on their own merits, I couldn’t help but be disappointed by this episode. It was as if the whole thing didn’t get out of first gear. In a series characterised by big twists, it was almost a twist in itself that the diamonds being swapped, shown early on, was nothing more than the most of basic and unvarnished of switcheroos. It’s clear that this episode was meant to be somewhat discombobulating – capped off by the outlandish appearance of Arlecchino’s athletic echo – but to what end?

The heist element of the episode was described by one review, ludicrously, as ‘Tarantinoesque’. Another argued that, at one point, we were supposed to believe that ‘we’re in a rehearsal of a play about a planned robbery’ – clearly not, for a litany of reasons, not least because you’d have to know the script to rehearse a play, and therefore looking ahead two pages wouldn’t be anything to brag about. Another described the episode as impossible to criticise because of the metatextual elements – which, of course, don’t automatically make something good. Mrs Brown’s Boys features plenty of fourth-wall breaking, and that’s hardly a critical darling, is it?

More generally, the unbridled positivity strikes me as unfounded, and perhaps an artefact of general affection for the series, and its return, rather than the individual merits of the episode. To me, this was one of the weaker episodes in the IN9 pantheon – and worryingly reminiscent, much like Series 5’s Misdirection, of an earlier, better episode.

But every series of IN9 has a couple of duff episodes, and I’m not worried that this represents any kind of reduction in quality. Instead, I find myself looking eagerly forward to next week’s episode.