James Norton said co-star Sarah Lancashire has given the “performance of her life” in Happy Valley as it returns for its third and final series.
Lancashire will play Sergeant Catherine Cawood in the hit BBC show set in West Yorkshire when it comes back after seven years in the New Year.
The last series of Happy Valley aired on BBC One in 2016.
The story is created by Sally Wainwright, who is behind At Home With The Braithwaites and Gentleman Jack.
It will return with Cawood discovering the remains of a gangland murder victim in a drained reservoir.
This leads her to her nemesis, the murderer and sex offender Tommy Lee Royce, played by Norton.
Norton said the show has been a “must see” as Lancashire is an “absolute legend in our industry, giving the performance of her life”.
He added: “I think it’s such a specific show about the very specific part of England, and you know the accents and the temperaments and sensibilities of those characters are quite specific to the area.”
Norton also said the ending “does not disappoint” and will see his character seven years later “still in prison serving multiple life sentences” and with “information about something we don’t know about yet”.
Ryan is now 16 and still living with Cawood and has ideas of his own about what kind of relationship he wants to have with the man, played by Norton, that she refuses to acknowledge as his father.
Connah spoke about working with Norton saying: “You see him on set between takes and he’s such a nice person, and then we’ll start filming and he’ll just instantly switch and there’s this psychopath.
“He brings a lot to the character and he does it really well.”
Both series one and two won the Baftas for drama series and writing, while Lancashire won the leading actress prize for the second series.
Happy Valley returns at 9pm on January 1 2023 on BBC One and BBC iPlayer.