Derry Girls star Nicola Coughlan features in new female-led comedy series Big Mood on C4

The fresh-faced actress first found fame in the sitcom Derry Girls, where she convincingly played schoolgirl Claire even though she was in her early thirties when the series began airing.

Since then, she’s also gone to take a key role in the hit Netflix period drama Bridgerton as reluctant debutante Penelope Featherington. (If you wondered why Claire was often missing from the third and final series of Derry Girls, it was due to filming conflicts between the two shows.)

Now though, she’s playing a woman who is leaving her twenties behind and negotiating adulthood in this series from writer Camilla Whitehill.

In theory, her character has her best mate Eddie (It’s a Sin’s Lydia West) beside her to help her with the transition.

They’ve been best friends for over a decade and have seen each other through thick and thin – and we’re not just talking about changing eyebrow trends.

Now though, they’ve come to a pivotal moment as their careers hang in the balance, and Maggie’s bipolar has resurfaced, leaving Eddie wondering whether it’s time they stopped living in each other’s pockets. Can their friendship survive as they move into the next stage of their life?

It’s something of a dream project for Nicola, who says: “When I first met Camilla Whitehill long, long ago, during the time of Indie Sleaze, I quickly realised she was one of the funniest and most talented people I’d ever met. It was always our dream for us to work on something together, and now Channel 4 are making that dream come true.”

Lydia West adds: “I’m so happy to be working with Camilla and Nicola on this project. The writing is genius, and the subject explores the mental health struggles that all of our generation face – coupled with how to navigate complicated, loving and nuanced friendship.”

In the opening episode of this double bill, Maggie goes back to her old school to deliver a talk to the kids, but she’s less interested in inspiring a new generation than she is in finding out if the hot history teacher Mr Wilson (Tim Downie) fancies her.

Eddie comes along for the ride, leaving Klent (Eamon Farren) in charge of her bar, but she becomes increasingly concerned about her friend’s behaviour.

In the second instalment, Maggie is experiencing a depressive episode, but it’s also her 30th birthday and Eddie doesn’t want to let the occasion go unmarked. But is dragging her pal to a celebration filled with friends and family really the right thing to do?

Meanwhile, Eddie also has a rodent infestation to deal with.

The impressive supporting cast includes Niamh Cusack, Luke Fetherston, Kate Fleetwood, Rob Gilbert, Sally Phillips and Joanna Page. No wonder writer Camilla says: “I am beside myself to be making this show with such an incredible team of people [and] a cast that I’d be jealous of if it wasn’t my cast.”