It's A Sin actor Callum Scott Howells says his role in a new thriller, set and filmed in Wales, offers "exactly the kind of challenge I love".

The Night They Vanished, an adaptation of the novel by Vanessa Savage, also stars Welsh actress Gabrielle Creevy.

The six-part mystery follows Anna (Creevy) as she discovers her childhood house is listed on a true‑crime website as the scene of her family's future deaths. While police say it's a hoax, Anna's family have vanished.

Scott Howells plays the role of Cai, who runs the website but denies posting the listing, describing the character as "charming, complicated and never quite what he seems".

Howells, from Pontypridd, Rhondda Cynon Taf, won the Bafta Cymru for best actor in 2021 for his portrayal of Colin in Russell T Davies' 1980s-set drama It's A Sin.

"He could be the love of Anna's life, or the centre of a terrifying conspiracy," he said of the role of Cai.

"Playing someone who keeps you guessing is exactly the kind of challenge I love."

Port Talbot-born Creevy appeared in Netflix series Black Doves and The Guest as well as award-winning drama In My Skin, for which she won Bafta Cymru best actress for her portrayal of teenage protagonist Bethany.

Creevy described the part of Anna as "a gift of a role".

"Anna is a firecracker - sharp, loyal, and carrying more hurt than she lets on," she said.

"The moment her past comes roaring back, she's forced into a nightmare she thought she had escaped.

"I can't wait for audiences to unravel the truth with her."

Fellow Welsh creative Angharad Elen - who adapted the original novel with Hannah Daniel - said she was "particularly proud to see the series set and filmed on my home turf".

The series is produced by CliffEdge Entertainment, part of BBC Studios, in association with Channel 4, and was backed by the Welsh government via Creative Wales.

It will air on Channel 4 later this year.