Cleddau/The One That Got Away: release date, cast, plot and everything we know

DI Ffion Lloyd (Elen Rhys) and DS Rick Sheldon (Richard Harrington) in Cleddau/The One That Got Away
Elen Rhys and Richard Harrington star in the six-part drama (Image credit: Blacklight / Banijay Rights)

Get ready for a dose of Welsh noir in Cleddau/The One That Got Away, a tale that combines "a gripping murder mystery with an electrifying love story".

The six-part Welsh-language drama, which comes to S4C and BBC iPlayer in October, stars Elen Rhys (The Mallorca Files) in her first major role in her mother tongue. 

She will star alongside Richard Harrington (Hinterland) in a gripping thriller created for the screen by Cath Tregenna, who returns to her native West Wales after writing for hit TV shows including Three Pines, Law & Order UK, Lewis, DCI Banks & The Bench.  

"I’m so excited to create and write my own series and share it with S4C audiences as that’s where my television career began," says Treganna. "It’s a privilege to write in the voice and accents that are part of my childhood and bring to bear what I’ve learnt in over 25 years of writing crime thrillers."

All six episodes are directed by Carmarthenshire-born Sion Ifan (Y Gyfrinach/The Secret).

Here's everything else we know about the six-part drama...

Cleddau/The One That Got Away release date

The six-part thriller was filmed on location on the Pembrokeshire coast in west Wales and in south Wales in the winter of 2023. 

It will premiere on Sunday, October 13 at 9 pm on S4C and BBC iPlayer.

An English language version of the show will also be produced for international audiences. Both will be distributed globally by Banijay Rights, the distribution arm of media and content powerhouse Banijay.

Elen Rhys plays DI Ffion Lloyd in Cleddau/The One That Got Away

Elen Rhys plays DI Ffion Lloyd  (Image credit: Blacklight / Banijay Rights)

Cleddau/The One That Got Away plot

An official synopsis reads as follows...

"Cleddau/ The One That Got Away is a murder mystery and a love story. The murder of a nurse sends shockwaves through a small-town community in this emotionally charged and psychologically driven thriller which twists and turns towards a heart-stopping finale. 

"The hunt for the killer, whose modus operandi echoes the historic Heart Knot Murders from twelve years ago, will re-unite ex-lovers, DI Ffion Lloyd and DS Rick Sheldon. In the Welsh coastal town of Pembroke Dock, in the dead of winter, they set about finding the killer while revisiting the past with devastating results. The historic murders were committed seven days apart so it’s a race against time to catch the killer before they strike again. Everything is at stake personally and professionally. 

Elen Rhys plays DI Ffion Lloyd and Richard Harrington plays DS Rick Sheldon in Cleddau/The One That Got Away

DI Ffion Lloyd and DS Rick Sheldon must unlock a dark secret (Image credit: Blacklight / Banijay Rights)

"Ffion and Rick will become our guiding light despite their flaws.  Their passion and chemistry will reignite until an explosive secret jeopardises not only their rekindled relationship but Rick’s integrity, reputation and career. In the shadow of death, Cleddau/ The One That Got Away is also a forensic examination of a love affair that may have ended but remains raw and unresolved.

"As suspects emerge, they will offer us a compelling window into mental health issues among small-town men, young and old, who are struggling to find a purpose in life. Steroid abuse, self-medication, PTSD, the care system and dementia will be explored, allowing us to tackle concerns that matter these days more than ever. 

"Cleddau/The One That Got Away operates in the grey areas of fallible human behavior. Murder can be deeply human. Love, in turn, can be murderous."

Rhian Blythe plays Helen Sheldon in Cleddau/The One That Got Away

Rhian Blythe plays Helen Sheldon (Image credit: Blacklight / Banijay Rights)

Cleddau/The One That Got Away cast

Elen Rhys (The Mallorca Files, Panic Button) and Richard Harrington (Hinterland, Fisherman's Friends:One and All) lead the cast as DI Ffion Lloyd and DS Rick Sheldon.

The rest of the cast is as follows... 

  • Rhian Blythe (Keeping Faith, Hidden) as Helen Sheldon 
  • Ioan Hefin (Gangs of London, Apostle) as DCI Alan Vaughan
  • Aled Pugh (The Light in the Hall, Hunky Dory) as DS Celyn Howells
  • Mali Ann Rees (Lost Boys and Fairies, Mammoth) as DC ‘Mogsy’ Morgan
  • Will Thomas (Tree on a Hill, Steeltown Murders) as Griff Lloyd
  • Ian Puleston-Davies (Coronation Street, DI Ray) as Paul Harvey 
  • Sharon Morgan (The Sin-Eater, Y Sŵn) as Delyth Lloyd 
  • Hannah Daniel (Creisis, Tree on a Hill) as Lisa Redwood 

Cleddau/The One That Got Away trailer

There's no trailer for this one yet, but we'll be sure to add it here as soon as one lands! 

Sean Marland

Sean is a Senior Feature writer for TV Times, What's On TV and TV & Satellite Week, who also writes for whattowatch.com. He's been covering the world of TV for over 15 years and in that time he's been lucky enough to interview stars like Ian McKellen, Tom Hardy and Kate Winslet. His favourite shows are I'm Alan Partridge, The Wire, People Just Do Nothing and Succession and in his spare time he enjoys drinking tea, doing crosswords and watching football.