Best Interests: release date, trailer, plot, cast and everything we know

Best Interests
Sharon Horgan plays the mother of a child with a life-threatening condition (Image credit: BBC)

Sharon Horgan and Michael Sheen lead the cast of Best Interests a "compelling and thought-provoking" new drama created by BAFTA-winning writer Jack Thorne. 

The highly-anticipated four-part series will tell the heartbreaking fictional story of two parents fighting to keep their 13 year-old daughter alive against medical advice.  

With TV hits such as National Treasure, Help, and The Virtues already on his CV, Thorne has shown a knack for tackling the most sensitive of subjects and viewers look set to be in for another emotional rollercoaster when this hits our screens.

“Best Interests cases are both compelling and revealing," said Jack Thorne in a BBC statement. 

"Our country has a very troubled relationship with disability and these cases put a spotlight on that. But our drama is first and foremost a love story and it needs incredible actors to bring it to life. Sharon Horgan and Michael Sheen lead a company of ridiculous talents that pull you into the most interesting of places.”

“As a parent of a three-year-old I've looked at the cases in the media about 'best interests' with some fascination and a little dread," he explains. 

"When the worst happens, how do you keep your head when everything around you feels wrong? We are going to try and tell a nuanced story that talks about this issue from all sides. ”

Here's everything we know about the four-part BBC One series...

Best Interests release date

Best Interests will air on BBC One and BBC iPlayer in four parts. The first two episodes will air as a double bill on Monday, June 12 and Tuesday, June 13 at 9 pm.

The third and fourth episodes will air the following week on Monday, June 19 and Tuesday, June 20 in the same time slot. 

Best Interests Sharon Horgan Michael Sheen

Sharon Horgan stars alongside Michael Sheen. (Image credit: BBC)

Is there a trailer for Best Interests? 

Yes, the trailer reveals the fight that Nicci and Andrew Lloyd have to keep their daughter, Marnie alive. It shows that the series is set to be a tough watch, but also an incredible one... 

What's the plot of Best Interests? 

A BBC synopsis reads...

"This is a story of a family driven apart by having to make choices no parent would ever want to make. Andrew and Nicci’s daughter, Marnie, has a life-threatening condition. 

"The doctors believe it is in her best interests to be allowed to die, but her loving family disagree. And so begins a fight that will take them through every stage of a legal process, as they struggle to contemplate this huge decision. Who decides? And in whose best interests will it be?"

Best Interests episode 1 recap - what happens? 

Nicci and Andrew are the proud and loving parents of Marnie (13) and Katie (17). But it hasn’t been easy. Marnie has a rare form of Congenital Muscular Dystrophy and has been in and out of hospital her whole life. 

Nicci and Andrew have learnt to adapt, caring for Marnie and Katie in the only way they know, however Marnie develops an infection that leads to her being rushed to hospital and put on a ventilator. Her health deteriorates to such an extent that the doctors believe it is in her best interests to withdraw care. 

They argue she is in pain, that the treatments are becoming too invasive. Her parents disagree. United in their anger, they both prepare to fight the medics on their decision. They believe Marnie has made it this far and it’s possible she might recover, that she has a good enough quality of life, one that is worth living. 

But with Marnie showing no clear signs of recovery, the first seeds of doubt begin to grow in Andrew: are they really doing the right thing?

Best Interests episode 2 recap - what happens? 

Andrew and Nicci’s united front starts to crack. Andrew has always been a doting father, holding his family together with gentle love and deep empathy. However, as Marnie’s condition worsens and a scan confirms brain damage, Andrew is realising that this might not be enough. 

He doesn’t feel Marnie’s current suffering is justified by any hope for her recovery, and thinks it might be time to let her go. For Nicci, who loves her daughter every bit as passionately as Andrew does, giving up is not an option. She will do anything to keep her daughter alive. Anything. Katie is caught in the middle of her warring parents. With Nicci and Andrew unable to reconcile their feelings about Marnie, Andrew moves out of the family home. 

Feeling increasingly isolated, Nicci turns to a Christian group who can help where Andrew has failed her. They plan to fundraise to mount a legal challenge to the hospital and to keep Marnie alive, maybe even take her abroad for further treatment. That means Nicci going public with their story, with all that entails. Nicci can see no other choice, whilst Andrew feels alone and further apart from his family than ever. 

Best Interests cast - who's in it? 

Sharon Horgan and Michael Sheen will lead the cast as married couple Nicci and Andrew Lloyd, who are parents of 13 year-old Marnie, who suffers from a rare form of Muscular Dystrophy. 

Horgan rose to fame as the star of BBC Three comedy Pulling and had a major hit with C4 sitcom Catastrophe, both of which she co-wrote. She has also appeared in HBO Comedy series, Divorce, and penned BBC2 sitcom Motherland. 

Meanwhile Sheen recently starred opposite David Tennant in Amazon Prime drama Good Omens and is famed for playing Tony Blair in The Queen, Nigel Clough in The Damned United and Chris Tarrant in ITV drama Quiz.  

Alison Oliver (Conversation with Friends) and Niamh Moriarty (Jack Thorne’s A Christmas Carol), will play their daughters 17 year-old Katie and her younger sister Marnie.

Additional cast include Noma Dumezweni (The Undoing) as Samantha, Chizzy Akudolu (Holby City) as Mercy, Des McAleer (Hope Street) as Eddie, Mat Fraser (His Dark Materials) as Greg, Gary Beadle (Grantchester) as Frank, Jack Morris (Strike) as Tom, Pippa Haywood (Bodyguard) as Judge Spottiswood, Shane Zaza (Happy Valley) as Fred, Lucian Msamati (Gangs of London) as Derek and Lisa McGrillis (Mum) as Brenda. 

Best Interests

Jack Thorne has penned the four-part series (Image credit: Getty)

Sharon Horgan said: "Best Interests broke me when I first read the script and then again after talking with Jack about it. Covid seems to have shone a closer light on the desperate inequalities that exist for our disabled community so this felt very timely. 

"It’s a big subject but it’s in Jack Thorne and Michael Keillor’s safe hands. I’m thrilled to be working on this story with a super talented cast, the wonderful Michael Sheen and Noma Dumezweni, and my gorgeous daughters; Alison Oliver and Niamh Moriarty." 

Michael Sheen said: “Jack Thorne is such an extraordinary writer and he has approached this incredibly important and urgent subject with humanity, honesty and humour. I feel very fortunate to be part of this production and to work with the brilliant Sharon Horgan and some of the most talented actors around.” 

Sean Marland

Sean is a Senior Feature writer for TV Times, What's On TV and TV & Satellite Week, who also writes for 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.