The Light in the Hall, the hit mystery drama from Channel 4 and S4C, has confirmed a new cast ahead of its return.

The series, which is filmed in both Welsh and English language, premiered in 2022 with a season starring Alexandra Roach and Iwan Rheon, focusing on a young journalist who investigates the disappearance of her friend.

Over two years on from its airing on Channel 4, the broadcaster has confirmed details of its second season, which has the subtitle of Still Waters. It will boast an all-new cast, with Siân Reese-Williams, Mark Lewis-Jones, Nia Roberts and Robert Glenister in the lead roles.

As per the logline, the action will return to the town of Llanemlyn, where a “controversial redevelopment plan to expand the reservoir is reigniting old tensions”. At the centre is journalist Caryl Huws (Reese-Williams), who becomes “captivated” by the story.

“[She] becomes entangled in a complex web of personal betrayal, familial secrets and dark mysteries,” reads the synopsis, which also teases details of a much-doubted imprisonment of a protestor from the 1990s.

sian reese williams, light in the hall still waters

S4C/Channel 4

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“The world of Llanemlyn returns with a mystery darker, deeper and more thrilling than ever,” said Gwenllian Gravelle, S4C’s Head of Film and Drama. “With a powerhouse cast and a story that grips from the first moment, this is one journey our S4C viewers won’t want to miss.”

“It has been wonderful to collaborate with such a talented cast and crew, and it was lovely to return to Llandovery to bring the world to life,” added producer Nora Ostler Spiteri, who also thanked Gravelle for their “warm support”.

Still Waters will premiere on S4C on 14 September, though its air date on Channel 4 is yet to be confirmed. The first season aired in the UK eight months after its premiere in Wales, so it could be a little while yet.

tom rhys harries, maeve courtier lilley, the light in the hall still waters

S4C/Channel 4

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The first season, which also starred Joanna Scanlan, received a generally positive response from viewers, with its user rating on IMDb currently standing at a solid 7.0 out of 10 from 2100 reviews.

“Overall this was an excellent drama with an outstanding story portrayed by actors at the top of their game,” wrote one user as they praised the “wonderful scenery”, while another viewer opined that the series was “truly engaging” and “absorbing”.

The Light in the Hall: Still Waters premieres on S4C on 14 September; its UK release date is yet to be confirmed.

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Reporter, Digital Spy George is a freelance writer who specialises in Movies and TV. After graduating with a degree in Film Studies and Journalism from De Montfort University, in which he analysed the early works of Richard Linklater for his dissertation, he wrote for several websites for GRV Media.  His film tastes vary from blockbusters like Mission: Impossible and John Wick to international directors such as Paolo Sorrentino and Hirokazu Kore-eda, and has attended both the London and Berlin film festivals.
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