In the 'Best Interests' Trailer, Two Parents Must Make a Heartbreaking Choice

Everyone should probably know going into Acorn TV's new limited series Best Interests that the drama is not an easy watch. But that's often true of television that deals with difficult or important subject matter. (Still, have your tissues handy.) The four-part drama tackles the emotionally fraught subject of best interest cases, legal proceedings that involve determining what is in the "best interest" of the child at its center. Often, this involves custody or visitation disputes between parents, but in this series, the question is quite literally one of life or death. 

Sharon Horgan (Bad Sisters) and Michael Sheen (Good Omens) play married couple Nicci and Andrew, whose daughter, Marnie, suffers from a rare form of muscular dystrophy. Following a severe infection that puts her on a ventilator, doctors believe it is in her best interest to be allowed to die naturally, but her parents disagree.  A legal battle ensues, forcing the pair to face heartbreaking and difficult decisions in the glaring light of the public eye, even as Marnie's steadily worsening condition begins to take an emotional toll on their relationship. 

The series is written by Jack Thorne (Joy) and originally aired on the BBC in the summer of 2025 to widespread critical acclaim. It snagged two BAFTA nominations, including one for Best Limited Series (which it ultimately lost to the equally difficult and excellent The Sixth Commandment). 

Here's the series' synopsis.

Nicci and Andrew are the proud and loving parents of Marnie and Katie. But life hasn’t been easy for their family. Marnie has a rare, life-limiting condition and as her health deteriorates, doctors believe it is in her best interests to withdraw care and allow her to die. Her parents 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. It's a story of a family driven apart by having to make choices no parent would ever want to make.

Alongside Horgan and Sheen, the ensemble cast includes Noma Dumezweni (Normal People) as Samantha, Chizzy Akudolu (Criminal Record) as Mercy, Des McAleer (Hope Street) as Eddie, Mat Fraser (Kaos) as Greg, Gary Beadle (Grantchester) as Frank, Jack Morris (Baptiste) as Tom, Pippa Haywood (The Doll Factory) as Judge Spottiswood, Shane Zaza (Happy Valley) as Fred, Lucian Msamati (Gangs of London) as Derek, and Lisa McGrillis (Rivals) as Brenda.

Best Interests is created and written by Thorne, directed by Michael Keillor (Roadkill), and produced by Jenny Frayn (The End of the F***ing World). Executive producers include Thorne, Horgan, and Sheen, alongside Sophie Gardiner (Howards End), Toby Bentley (Kiri), and Lucy Richer for BBC One.

All four episodes of Best Interests will premiere on Acorn TV on Monday, February 17, 2025.