Happy Valley creator Sally Wainwright speaks about show's return and why the series is such a hit with audiences

The BBC drama first hit our screens back in 2014 and is the work of Calderdale writer and director Sally Wainwright, who has also penned Last Tango in Halifax and Gentleman Jack.

The series follows Sergeant Catherine Cawood, played by Sarah Lancashire, who is back on the trail of murderer and sex offender Tommy Lee Royce, played by James Norton.

“It’s not a police procedural, it’s not a crime show,” said Sally. “It’s really about Catherine and about what happened to her in the past and this weird crooked relationship she has with this man who affected her life so badly.”

It was a documentary and another Calderdale-filmed drama that inspired Sally to write Happy Valley: “I saw a documentary by Jez Lewis called Shed Your Tears and Walk Away and it was about drug and alcohol problems, specifically in Hebden Bridge.

"The other influence was that, when I was a kid, there was a series called Juliet Bravo, which I really, really liked. It was actually not filmed far from Hebden Bridge, it was filmed in Todmorden. It was about a female police inspector and it was a really good show.”

Since series one Happy Valley has been a huge hit with audiences.

Sally said: “It’s odd with Happy Valley, so many people talk about it in such a way that I do now believe it’s pretty good! I did ask someone the other day, ‘what is it that you think?’, and she said ‘the characters and the performances and the stories’.

"You know the truth is it’s just an alchemy, just an alchemy that some shows somehow manage to press buttons with people. I guess it’s just one of those. You kind of hit a patch of gold, a seam of gold in it somehow. It does always seem to capture people’s imaginations when you are writing about things that are on the wrong side of the law.”

The latest series has been a long wait for fans, but the hiatus has all been planned.

Sally explained: “I waited six years because I wanted to get to a point where Ryan would be old enough to start making choices about whether he wanted to have a relationship with his dad or not. And could he have a relationship with his dad, and how would Catherine feel about that? I really wanted to be able to explore that. It’s been great that we got Rhys (Connah) back to play Ryan which has been fantastic, and he has done a really lovely job in that.

"That was always the intention, to have a gap and it has worked out just about right. Just the right period of time because he is now 16, so he can travel places by himself, he can make choices. He can do things behind Catherine’s back. The intention developed through conversations I had with Sarah to make it a three-parter, to make a trilogy. We always said this would be the final season and it is very definitely is the final season.”

Happy Valley will return on BBC One on New Year’s Day at 9pm.