Sarah Lancashire will reprise her role as Sergeant Catherine Cawood when Happy Valley returns for a third and final series, the BBC has announced.

Filming on six new episodes of the smash hit drama will begin in 2022, with James Norton and Siobhan Finneran also confirmed to return.

The third series will be the final chapter of the Happy Valley story, created by writer Sally Wainwright.

National Prince’s Trust Awards 2020
James Norton will also return for the third series (Ian West/PA)

Wainwright has returned to write the new episodes, which will see Norton back as murderer and sex offender Tommy Lee Royce and Finneran back as Catherine’s sister Clare.

The new series will find Catherine as she discovers the remains of a gangland murder victim in a drained reservoir, sparking a chain of events that unwittingly leads her straight back to Royce.

Her grandson Ryan is now 16 and still living with Catherine, but he has ideas of his own about what kind of relationship he wants to have with the man Catherine refuses to acknowledge as his father.

Virgin TV British Academy Television Awards 2017 – Arrivals – London
Siobhan Finneran (Matt Crossick/PA)

Still battling the seemingly never-ending problem of drugs in the valley and those who supply them, Catherine is on the cusp of retirement.

Wainwright said: “I’m delighted to find myself back in the world of Catherine Cawood and her family and colleagues for the final instalment of the Happy Valley trilogy.

“It’s been wonderful to see the lasting impact this series has had on audiences all over the world.

“I’m thrilled that Sarah, James and Siobhan are back on board for what I hope will be the best season yet, and thrilled once again to be working with the wonderful team at Lookout Point, the BBC and our new colleagues at AMC.”

The last series of Happy Valley aired on BBC One in 2016. Both series one and two won the Baftas for drama series and writing, while Lancashire won the leading actress prize for the second series.

Virgin TV British Academy Television Awards 2017 – Press Room – London
The cast of Happy Valley at the Baftas (Ian West/PA)

Lancashire said: “It’s time to let the dog see the rabbit,” while Norton added: “To take on Tommy one final time is a wonderful and daunting privilege, and something I’ve been looking forward to since we wrapped the last series, six years ago.

“I’m so excited to be working with the insanely talented Sally and Sarah again. Thinking we should all go on one last barge holiday, for old times’ sake.”

Filming will take place in and around West Yorkshire in 2022 and series three will premiere on BBC One and BBC iPlayer.

The first two series of Happy Valley are available to watch on iPlayer now.