James Norton on Happy Valley - “Tommy Lee Royce is an enigma and a puzzle and a kind of terrifying mess”

“Genuinely, I am still kind of working him out."

"What we know about Tommy is that he had a very abusive childhood and lives with horrible trauma. We know that because Sally has written it into the script and he is very, very mistrustful of the world. He sees everything and everyone as a hostility and a potential threat. I think he feels like the way to live a happy life in his head is to be on the defensive and to attack before he gets attacked. It’s quite a sad, lonely space that Tommy lives in.”

Happy Valley is set in the Calder Valley and follows Sergeant Catherine Cawood, played by Sarah Lancashire. Her grandson, Ryan (Rhys Connah), is now sixteen and has ideas of his own about the kind of relationship he wants to have with the man Catherine refuses to acknowledge as his father, Tommy Lee Royce.

Series three will see the enemies cross paths once again. James said: "The relationship between Catherine and Tommy is kind of everything, at least for Tommy. Tommy has Catherine and Ryan, they are the big two poles of his existence. Catherine has her family and does not want to think about Tommy. Tommy constantly forces his way into her life and her consciousness.

"They are in the best way, in that sort of old-fashioned way, epic adversaries pitched against each other. They are obsessed with each other, there’s a kind of deep, deep hatred in the way that when you think about someone that you hate they inhabit part of your consciousness. There’s a sort of, not love at all but, there is a kind of connection and affinity.

"There’s a certain kind of shared experience they have in that they both obsess about each other. In that way they are inextricably linked and will always be in some way married together.”

At the start of series three, which takes place seven years on from the second series, Tommy is still in prison serving multiple life sentences. “But he has changed,” James said. “He has moved on and grown and he has matured. He has calmed down and there is a definite shift in his demeanour and his temperament. I think that’s because for the first time in a long time he has got hope.”

Happy Valley has seen huge success both in the UK and overseas, winning several awards including Baftas for best drama series.

James said: “Happy Valley is a must-see because you have one of the best writers in the world, at the top of her game. You have Sarah Lancashire, also an absolute legend in our industry, giving the performance of her life.

"An amazing cast, Siobhan Finneran and others. It’s just a great community, a great group of people doing great work. I just think it’s a great story, it’s a great thriller. We have got fantastic characters driving it forward. We love playing the characters because they are so beautifully drawn.”