Reach Screen Time spoke exclusively to Mark Lewis Jones about his new seriesThree people stand in front of a reservoir The Light in the Hall: Still Waters is a follow-up to the 2022 thriller (Image: S4C)

One of the stars of a brand new thriller has opened up about the challenging aspects of shooting the series, as others have watched another compelling new series.

Acclaimed Welsh star Mark Lewis Jones spoke exclusively to Reach Screen Time about his gripping new TV drama series Y Golau: Dŵr (The Light in the Hall: Still Waters).

The Crown and Chernobyl star said it could be tough filming on night shoots while facing the bitterly cold elements. He explained: “Sometimes those exterior things can be a distraction. So, I guess if there is a challenge, it’s making sure that you don’t get overwhelmed by the scenery, the weather and the time of day.”

The 61-year-old actor described the dramatic backdrop as “another character”, saying the filming locations in Caernarfonshire were “so impressive”. He added: “It’s a wonder to me that it hasn’t been used [for filming] before” and teased that it had “a big impact on the story”.

The Light in the Hall: Still Waters serves as a sequel to 2022’s The Light in the Hall and returns to the fictional village of Llanemlyn.

A man in black smiles Mark Lewis Jones stars in The Light in the Hall: Still Waters(Image: S4C)READ MORE: Outlander star Mark Lewis Jones transforms for new role in Welsh mystery thrillerREAD MORE: Netflix’s Hostage star Mark Lewis Jones reveals the one thing that ‘nailed’ role for him

The drama follows a controversial redevelopment plan to expand the local reservoir, reigniting old tensions.

Jones portrays Rhys Owens, who has been imprisoned for killing his cousin in a reservoir explosion back in 1995, deemed an act of terrorism. Rhys is finally out after serving time and is claiming his innocence as a fresh expansion of the reservoir looms.

The story catches the attention of young journalist Caryl Huws (played by Siân Reese-Williams), who starts to investigate.

Caryl soon finds herself tangled up in a complex web of personal betrayal, family secrets and dark mysteries after her inquiries start raising questions about Rhys’ guilt and a potential miscarriage of justice.

A reservoir against mountains Filming at the sweeping location of The Light in the Hall: Still Waters had its challenges (Image: S4C)

Like many S4C productions, including Keep Faith, Hinterland and most recently Mudtown, The Light in the Hall: Still Waters was filmed back-to-back in both English and Welsh.

The process of consecutive filming in the two languages required the cast to switch between English and Welsh in between takes.

Addressing filming in two different languages simultaneously, Jones admitted he’d “got used” to doing it after shooting so many shows over the years. He went on to explain how “you do switch quite quickly between one and the other” and described it as a “mental switch”.

Interestingly, Jones said his performances were “slightly different” in each language. However, he said it was tricky to pinpoint the differences because they were so “subtle” and worked on a “deeper level”.

A young man and a woman stand on a bridge Tom Rhys Harries stars in The Light in the Hall: Still Waters(Image: S4C)

“The language has a different effect on people. The Welsh language has a completely different social background to the English language, so if you’re speaking Welsh, you’re kind of representing someone different to a person speaking English in a Welsh community,” Jones said.

He said that regardless of where a person lived in Wales and their accent, there were no “assumptions” or “social strata”, unlike in English.

Jones said that even if the audience didn’t pick up on the differences between the two version, “as an actor” he felt them.

Y Golau: Dwr will air in Welsh with English subtitles on S4C from September 14 at 9pm

Y Golau: Dwr drops as a boxset afterwards on BBC iPlayer and S4C Clic