It’s a bold move for an anthology show to kick off a new series with possibly its most bonkers entry yet. Reece Shearsmith and Steve Pemberton have talked about how (aside from budgetary constraints) they essentially have free rein to do what they want with Inside No. 9, and that BBC head of comedy Shane Allen is such a fan of the show that he doesn’t interfere with it at all because he doesn’t want to know any spoilers. The upshot of this creative freedom is that we’ve had episodes ranging from silent comedy and Shakespearean farce to gothic horror and kitchen-sink drama… and series 6 begins with something that’s part Reservoir Dogs-Esque heist, part commedia dell’arte. It’s so demented that it will probably divide viewers between thinking that Shearsmith and Pemberton have either hit new heights of genius or completely gone off the deep end. Personally, I’m leaning towards the former.

If you aren’t familiar with commedia dell’arte, you don’t need to be an expert to get the gist. It’s a type of Italian theatrical comedy, dating back to the 16th century, in which male characters wear masks while female characters don’t, and certain archetypal characters (various master/servant figures) recur across multiple plays. Inside No. 9’s Wuthering Heist, directed by Guillem Morales, combines commedia dell’arte with another genre where mask-wearing is common – the heist movie. So we see a motley gang of criminals meeting before and after they execute a plan to steal some diamonds. Of course, the plan doesn’t go as smoothly as anticipated, and they have to face the possibility that there’s a rat in the group. Meanwhile, there’s an injury to deal with, an attempt to swap out the real diamonds for fakes, and (drawing more from the commedia dell’arte side) a misunderstanding with a romantic letter.

Inside No. 9 tends to begin each series with an ensemble comedy episode, and this one is no exception. At the lower end of the gang hierarchy, we’ve got Arlo (Kevin Bishop), a lovable fool who seems more interested in getting hold of a sandwich than a bag of diamonds, and Columbina (Gemma Whelan), who talks directly to camera and provides us with a running commentary of the story. She likes to think of it as “Miranda-ing” as opposed to “Fleabagging.” Then there’s menacing boss Pantalone (Paterson Joseph), with wild eyes under a pointy red mask, and his posh daughter Hortensia (Rosa Robson). Shearsmith adopts an outrageous Italian accent as military man Scaramouche, while Pemberton plays a character known simply as the Doctor. Mario (Dino Kelly) is the Doctor’s handsome but dim-witted son.

Due to the commedia dell’arte influence, this is one of Inside No. 9’s more gag-heavy episodes, and the humour is unashamedly silly. There’s a doctor fainting at the sight of blood (and at one point, ketchup), a mix-up between the words bomb and bum (thanks to Shearsmith’s ridiculous accent), and an emotional speech punctuated by a run of place name puns. During a stand-off, one man tells another “I’ve dreamed of having your weapon in my face, but not like this.” The jokes come so thick and fast that some of the double entendres only registered with me on a second viewing.

There’s already so much to digest in the episode, and the comedy is so quick and fun, that I could have done without some of the meta comments from Columbina that undermine the set-up. Talking to the audience early on, she informs us “it’s series 6 – you’ve got to allow for a certain artistic exhaustion”; on another occasion, she tells us to “stick with me on these bits and we’ll get through them as quickly as possible.” Just as series 4 opener Zanzibar was a Shakespearean comedy set in a hotel, I would have happily accepted Wuthering Heist as commedia dell’arte set around a heist, without the additional element of an actor breaking character to reference the Cook’d and Bomb’d forum. For me, the episode is at its best when it leans fully into the combination of high-stakes heist drama and all-out daft humour.

As usual, the BBC is being secretive about what’s coming up in this series of Inside No. 9, but so far, we know that we can expect an episode about a superfan meeting the creator of his favourite show to talk about the unsatisfactory way it ended, as well as a story where Line of Duty’s Adrian Dunbar plays himself. Other guest stars include Sian Clifford, Lindsay Duncan, Nick Mohammed, Sarah Parish and Derek Jacobi. Although it may prove to be divisive, and any newcomers may be baffled, Wuthering Heist is certainly an audacious start to the series, proving that (despite what Columbina claims) Shearsmith and Pemberton are far from running out of ideas.

                              Inside No.9 Continues Monday at 9.00pm on BBC Two

Contributed by Sophie Davies.