The third season of the wonderful Inside No 9 continues with the usual array of great guest stars popping up including Tamzin Outhwaite and Keeley Hawes

A star-studded cast has joined Inside No 9 creators Reece Shearsmith and Steve Pemberton to add an extra layer of fabulous to the pair's third series.

The stand-alone format means that even newcomers to the dark comedy anthology can dip in and out of the show as each film is set in a different location, with a different style and tone every week.

New settings for this series have included a restaurant after closing time, an Alpine lodge, a professor's study and, this week, a karaoke booth. All are linked by one thing only: the number nine.

Guest stars have included Philip Glenister, Jason Watkins, Alexander Roach, Rula Lenska, Jessica Raine, Derek Jacobi and tonight, Tamzin Outhwaite of New Tricks and EastEnders' fame and Sarah Hadland, from Miranda, will be joining Shearsmith and Pemberton in Empty Orchestra.

What better way to celebrate Roger's promotion than a full-on, old-school karaoke session in an evening full of hopes, dreams, intrigue, romance, betrayal and singing (this is my idea of hell - singing in the shower is one thing, singing in front of people is quite another).

'I've always loved inside No.9, the concept is amazing,' said Tamzin, 'I always remember the silent episode that my friend Dennis Lawson was in - there was no dialogue at all, it was absolute genius.

'When I read the script I thought, this is brilliant - there wasn't any doubt in my mind. And when I found out that Sarah Hadland was in it too, playing my character's love rival, that was brilliant too because she's an old friend of mine. It was the icing on the cake, or the cherry on the top of the icing.

'My character Connie is not a particularly nice human being, which I liked. She's flawed and messed up and she treats people like objects; it's all about what she wants. She's one of those people who's popular, who everyone likes, but actually she's got a streak in her that's quite nasty.'

Tamzin added that she had worked with Pemberton before, in an episode of Hotel Babylon, and that her scenes in Number 9 involved working with him again.

'We were all on set at the same time, all in one room together. It was quite difficult to control the noise with me, Sarah Hadland, Javone Prince, Reece and Steve all talking loudly, it must have been a director's nightmare,' she laughed.

'It was like we were all really at the party in fancy dress outfits having a chat. So we had to keep reminding ourselves that we were working. I think it's a good sign, that we were all quite excitable.

'Everybody wants to do an Inside No 9. It's like one of those boxes that you have to tick. It's an award-winning show that you just think, 'oh I'd love to be in one of those' - because they're so interesting, dark and funny at the same time.'

Her favourite scene, she explained, was with Hadland: 'Sarah and I play love rivals and we end up having to sing, not necessarily well, and that ends in a situation that is quite dark but quite funny. It's very close to the bone and sometimes it's really uncomfortable, and that discomfort makes you want to laugh: we're not meant to be brilliant, we're meant to be in a karaoke booth!'

Next week, Inside No 9 is set in an ordinary-seeming home where David (Shearsmith) and Louise (Keeley Hawes) and their daughter live. But when David brings home a single black shoe, the arrival becomes a life-changing obsession that threatens to come between them all.

Keeley explained that the show reminded her of Roald Dahl's Tales Of The Unexpected, an Anglia Television programme she remembers from her childhood when she would watch it with her family religiously.

'When I was asked to do it I was actually filming The Durrells, but it only takes a week to film an episode of Inside No.9. So I finished The Durrells on the Friday and then started Inside No.9 on the Monday, which was very odd, going from Louisa to Louise over the weekend, but I loved it,' she said.

'It was so different from what I had just been doing. I just think they're so clever and the whole concept is so unusual. I loved the script, which made me laugh out loud – it's quite a dark episode. There are four of us in it but the majority of the time it was just the three of us, which was quite intense. The whole thing is just a really lovely package and a it was a very flattering thing to be asked to do.

'When we meet David and Louise we think they are fairly unassuming and normal - which they are, they're getting along with things. Louise's husband is a stay-at-home husband looking after their little girl and she goes out to work, she's a career woman trying to balance everything. So I could relate to that: trying to juggle lots in her life.

'We have a very long dinner scene with just the three of us - I got the giggles at one point during that because they're both incredibly funny, the writing is so funny - really dark and dry - so it was inevitable really.'

* Inside No 9 is on BBC2 tonight at 10pm.