Death. Dancing. Denial. Depression. Dishes best served cold. Who doesn’t love a dark, twisty tale from the BBC Two television phenomenon that is Inside No. 9?

Not many, judging by the capacity audience last month at the Vue Manchester’s Screen 18 (18 is twice nine, after all), there to see an exclusive preview of the series 8 finale, The Last Weekend.

“It’s nerve-racking,” said Reece Shearsmith, co-creator, co-writer and actor, when asked by Joe McGrath of BBC Radio Manchester how he feels about the unveiling of new work. “You fear the reaction to it. The bar is high for us, with what we’ve done so far.”

And the exposure on such a huge screen? Ian Bevitt, director of The Last Weekend, was very happy: “Ian McKellen said that [good film acting] is all in the eyes. It’s definitely there in the eyes, especially at the end.”

The beginning, however – the inspiration for the episode – came not from the subject matter, but from the structure. “In several episodes of Inside No 9, we’ve parcelled out how you see the story into chapters,” explained Steve Pemberton, the other co-creator, co-writer and actor.

“We did it with The Understudy, about the theatre,” Pemberton continued, “so we were able to break down the Scottish play (Macbeth to the non-superstitious) into five acts. To Have and to Hold was the marriage vows. This one was [psychiatrist Elisabeth Kübler-Ross’s] stages of grief.”

For Bevitt, the scary part was getting the script. “I’ve read a lot of scripts in my time, but it was watertight, airtight. There’s not a loose line or even word in it. My biggest fear was, ‘What if it overruns? How am I going to trim anything?’ But… it fitted perfectly.”

Of course, the setting is a big element in the story. “It needed to be somewhere isolated,” said Pemberton. “We knew we were going to film series 8 in and around Manchester, so we knew we were likely to find a nice lakeside setting.”

Bevitt took up the story. “It was a tricky thing… because it was nearly an hour away from the studios, so we lost quite a bit of filming time every day. And it was perfect on screen. But what you don’t see is an industrial unit to one side and somebody’s house on the other, so it was all the ‘magic of television’ stuff to make it look right.”

In The Last Weekend, Shearsmith and Pemberton play a gay couple. “It’s fun to do,” Shearsmith said. “We’d done that before, in the first ever episode of Inside No. 9, Sardines.” And since the pair have been working together for “more than 30 years”, the warm chemistry they automatically share comes across effortlessly.

The other character in the episode, played by Sheila Reid (Benidorm, Call The Midwife), was inspired by the ­Scottish assistant of the promoter with whom Pemberton and Shearsmith worked years before at the Edinburgh Festival. “She just said to us one day, ‘I love cheese’, and we’ve been saying this to each other ever since for years, which is why [Glasgow-born Reid’s] character is Scottish.”

Pemberton knew that “Sheila was just perfect for the role.” This led to another element in the plot and another twist in the tale. “It all came together quite deliciously,” he said meaningfully.

Bevitt slotted smoothly into this tight-knit team. As a northern TV director he had worked previously with many of the crew, including producer Kim Crowther, editor Patrick Hall and director of photography Len Gowing.

Filming in Manchester was great, said Shearsmith. “If you’re at home, you have real life still going on… All we had to concentrate on [here] was just doing the best we could do.… Bringing the work up North, [we had] extra money… it has really helped the show.”

To Pemberton, originally from Blackburn in Lancashire, it was a “home from home”. “For this series and the one before we’ve been bringing in new directors, new directors of photography, new designers – and it refreshes the show.…

“We had an absolutely fantastic crew… and we’re hopefully going to come back and do more.”

Bevitt concurred: “At Yorkshire TV and Granada, there’s always been a really strong hub of production, and it’s even bigger now: there are so many different programmes getting made.”

As for the music in this episode, McGrath described it as “a real earworm”. Pemberton told the audience: “We had written lyrics and sent them off to [composer] Christian Henson, who’s done all our music for Inside No. 9, and we asked, ‘Can you find a tune in this, 1990s boy-band style?’ He tweaked the lyrics and his assistant sang on it.”

For the dance moves, they got in a choreographer. “There are more lyrics, so we could flesh it out if there’s a demand,” joked Pemberton.

As with the song, Pemberton and Shearsmith write everything together. “We enjoy the process, coming up with new ideas and making each other laugh.… We do a lot of talking, then we write an episode and, as soon as that’s done, we try to write another. One that differs entirely from the one we’ve just written. And in that way we try to build up a series of episodes that have different flavours.”

In series eight, for example, there is “one which is very comic, and another which is more dark and thriller-y, and not as naturalistic as [The Last Weekend]”, Pemberton said. Yet another, Mother’s Ruin, “is a cross between necromancy and gangster film”, so already “there’s a great variety, which is what we love as writers and as actors”.

They have a list of “dream stars” they would love to work with in the next series. “We’ve had Sir Ian McKellen in our sights,” said Shearsmith, “but we haven’t had a part that has been right for him yet.”

“We never write for particular actors,” added Pemberton. “We just write characters. And there’s such a wealth of acting talent, both comedic and dramatic, we’ve only just scratched the surface.”

Pushed on this, he admitted: “We’d have back someone we’ve used before: Julie Hesmondhalgh… and I’ve always wanted to work with Siobhan Finneran.”

The next series, fittingly series 9, will be the last. “We’re very pleased,” said Shearsmith, “with our lot from the BBC, where we’ve been allowed all these years… to explore all these different ways of telling a story.”

This included, added Pemberton, “filming a live special… An extraordinary achievement.”

Report by Carole Solazzo. The RTS North West Inside No 9 event was held on 19 April at the Vue cinema, Manchester Printworks, and produced by RTS North West in association with Plank PR.