Record-breaking BBC drama Keeping Faith has been commissioned for a second series, which will air next year.
Filmed in English and Welsh, the first series attracted audiences of more than 300,000 on TV, breaking iPlayer records with about nine million downloads.
It was broadcast first on Welsh language channel S4C as Un Bore Mercher (One Wednesday Morning) and later as Keeping Faith on BBC One.
After ending on a twist, series two will rejoin Faith Howells.
Played by Eve Myles, she will be seen attempting to pick up the pieces of her life and marriage following the sudden disappearance of her husband in series one.
Produced by Vox Pictures and co-commissioned by S4C and BBC Wales, it is the broadcaster's most successful non-network drama in over 20 years.
Nick Andrews, BBC Wales' head of commissioning said: "What happens next to Faith is anyone's guess but what's beyond doubt is Eve Myles' ability to captivate the nation for a second time.
"We're enjoying an incredible era for Welsh dramas at the moment and this is set to continue.
"It's a superb example of what's possible when broadcasters such as BBC Wales and S4C work together on projects of scale and ambition."
S4C's Director of Content Amanda Rees said the show will first air on S4C.
"This exceptional, most talked about drama demonstrates that great things can happen when broadcasters join forces and is testament to the outstanding acting and producing talents that Wales has to offer," she added.
Welsh Government Economy Secretary Ken Skates said the last two years had been the government's busiest in supporting TV and film.
"We are working extremely hard to continue to attract high-end TV and film productions to Wales, and to ensure we maximise the associated economic benefits," he said.
"High profile productions such as Un Bore Mercher / Keeping Faith [cements] Wales' reputation as a five star place to film."