Steve Pemberton and Reece Shearsmith on the new Inside No 9 episode, Wuthering Heist

Steve Pemberton and Reece Shearsmith are known for borrowing from other genres in Inside No 9, incorporating the likes of Shakespearean iambic pentameter, silent movie tropes and 1970s horror film ideas into their work.

But the opening episode of the new sixth series features one of the more unusual mash-ups: a heist movie combined with the 16th century Italian theatrical tradition of commedia dell’arte, the masked slapstick comedy which popularised the likes of Mr Punch and the harlequin.

And the idea, Pemberton reveals, stemmed entirely from the pun he came up with for the title: Wuthering Heist.

‘I remember being absolutely thrilled with that title,’ he says: ‘I was really pleased myself.

‘Then we sent it to Adam [Tandy the producer] and his first note back "Was what a terrible title, I'm sure you can do better."  No! that is the best title we've ever had.

‘That playfulness of Wuthering Heist helped inform the fact that we were going to mash these two genres together.’

Shearsmith admits that he had concerns about the shifts required to flip between broad, highly stylised comedy, and the more dramatic elements of a heist story.

‘How do you sort of marry tonally those two elements?’ he said. ‘That was what was delicious about the whole concept, but also very difficult to get especially in rehearsal, we were forever dancing around what the tone of it was.

‘I remember it being the longest time or during filming, where I felt still slightly unsure about what level to pitch it.

‘After a day  it was fine, but normally, you hit the ground running and you're sorted that out. But he's still felt slightly nebulous.

’In the end,  you just do it and people will watch this episode and they'll think "Why they're wearing masks? Oh, it's because they're doing a robbery. That's fine."  They won't really even think about the archetypal tropes and characters from commedia. That will just become a side issue.

‘If you know it,  it's layered with us playing those typical characters. It's very silly and meta and broad, and yet also, I think, has the truth of the situation: when people get hurt, they bleed.

‘We wanted to play that slight dichotomy of the fact that it's very silly but yet there is real peril at the heart of it and that was tricky to get right.

’In the end, you watch it and you just enjoy it for what it is, but you sort of get what we were what we were doing. I hope!’

Working with the masks was something of a challenge for the cast, including guest stars Kevin Bishop, Gemma Whelan and Paterson Joseph, as it limited their expressions. And that meant a lot more rehearsal.

‘We did a full week's rehearsal, which we never normally do,’ Pemberton says.

‘Unfortunately, Paterson (left) wasn’t unable to join us because he had to self-isolate having just come off another job. And I think he was quite nervous turning up on the first day given that we'd done all this rehearsal, but I think that he had studied this - as has anyone who has done drama- had done  some commedia dell'arte mask work.

‘He did brilliantly with his mask, I think when you watch the detail of what he's doing the little turns of the  head, the use of that long nose - and we wanted the Pantalone in our version to be a really threatening character, the gangster. And  I think Patterson absolutely nailed that.’

And for the last word on how daunting it is to mash up two genres, he adds: ‘We love going into  quite scary situations where we don't know how we're going to achieve it, because we're almost inventing our own new way of storytelling. And that for me, is one of the joys of Inside No 9.’

• Inside No 9: Wuthering Heist airs on Monday at 9.30pm

Published: 7 May 2021