The Other One season 1: everything you need to know about the sibling comedy

Rebecca Front, Ellie White, Lauren Socha and Siobhan Finneran in The Other One
(Image credit: BBC/Cave Bear/Tiger Aspect/Vish Sharma)

Happy Valley's Siobhan Finneran and Poldark's Rebecca Front star in a new comedy about a secret family...

The Other One is a new sitcom about two half-sisters who share the same name. Here's everything we know about the show.

The Other One season 1: when does it begin?

The seven-part series launches on 5 June 2021 on BBC1. All episodes will be available as a box set on BBC iPlayer.

The Other One season 1 plot: what's it about?

After her father Colin's sudden death, Catherine Walcott discovers that he had been having an affair with a woman called Marilyn for a long time. Not only that, but they had a daughter together — also named Catherine Walcott.

Marilyn, Cat, Cathy and Tess try to scatter Colin's ashes in The Other One

Colin's untimely death brings Marilyn, Cat, Cathy and Tess together (Picture: BBC) (Image credit: BBC/Tiger Aspect Productions/Matt Squires)

While Cathy's mum Tess struggles to come to terms with the fact that her husband was leading a secret double life, Cathy reluctantly gets to know her new half-sister Cat. The two women —  born just five days apart —  seem very different at first, but gradually discover they have more in common than just their father.


Who's in it?

Ellie White (Princess Beatrice in The Windsors) plays highly-strung Cathy and Misfits star Lauren Socha is her laid-back half-sister Cat.

"Cathy is one of those people who clearly struggles having close friends and letting people into her life," says Ellie. "She doesn't know what to do with Cat, because Cat's so warm and lovely and kind to her. That completely opens up another side of Cathy."

Cat and Cathy enjoy some drinks on a boat on dry land

Sisters Cat and Cathy realise they're more alike than they thought (Picture: BBC) (Image credit: BBC/Cave Bear/Tiger Aspect/Vish Sharma)

"Cat has a heart of gold," adds Lauren. "She's very in-your-face, which makes her more loveable. She doesn't have a filter, or if she does, she's not aware of how direct she is. The two of them are completely opposite people, which is brilliant."

Poldark's Rebecca Front also stars as Tess, Cathy's mother. Siobhan Finneran (Happy Valley) plays Cat's mum Marilyn.

"Tess is a very tightly-wound woman," reveals Rebecca. "Then this terrible thing happens to her, which would be an awful thing for anybody to cope with. I don't know who would deal with it well, but certainly, Tess does not! She closes herself off more and more from the world and will not accept the reality that she's been faced with. She becomes an even more difficult woman — but she wouldn't see it that way!"

"Marilyn has been aware of Tess's existence the entire time," says Siobhan. "She hasn't been dealt the double blow that Tess has — that she's lost the love of her life, and he's been cheating on her for 30 years. There's a kind of fascination. She wants to meet this woman that Colin loved and spent his life with."

Tess, Cathy and Marcus attend Colin's funeral in The Other One

An awkward atmosphere at Colin's funeral for Tess, Cathy and Marcus (Picture: BBC) (Image credit: BBC/Tiger Aspect Productions/Matt Squires)

Completing the regular cast is Amit Shah (Grace) as Cathy's fiancé Marcus, who is trying to win back her trust after a recent indiscretion with a work colleague.

"He's essentially a good guy," explains Amit. "But he has flaws like all these characters do. He's made this monumental error that's put his relationship with Catherine on the rocks. As the story unfolds, he attempts to salvage their relationship."

Stephen Tompkinson and Rebecca Front as Mr Shippen and Tess

Stephen Tompkinson guest stars in episode two as Cathy's former teacher, Mr Shippen (Picture: BBC) (Image credit: BBC/Cave Bear/Tiger Aspect/Vish Sharma)

Guest stars over the course of the series include Neil Pearson, Stephen Tompkinson and Caroline Quentin.

What else do we know about The Other One season 1?

  • The show originally aired as a single-episode pilot for BBC2 in 2017. That original episode forms the first part of this series.
  • The Other One was filmed on location in and around Manchester and Bolton.
  • The series was inspired by a true story, according to creator Holly Walsh: "My friend told me a story about how this happened to a friend of their parents in the 70s," she says. "They had two families, and called their kids the same name to avoid confusion. Weirdly, since the pilot went out, people have come up to me and gone 'oh yeah, that happened to my mate'. It seems more common than you might think!"
Steven Perkins
Staff Writer for TV & Satellite Week, TV Times, What's On TV and

Steven Perkins is a Staff Writer for TV & Satellite Week, TV Times, What's On TV and, who has been writing about TV professionally since 2008. He was previously the TV Editor for Inside Soap before taking up his current role in 2020. He loves everything from gritty dramas to docusoaps about airports and thinks about the Eurovision Song Contest all year round.