TV review: Best Interests is a gruelling drama — with Sharon Horgan and Cork actress Alison Oliver

This is about the parents of a seriously ill child — the parents who know their way around the ward, the parents who have obviously spent too many hours here already

Best Interests with Andrew (Michael Sheen) and Nicci (Sharon Horgan). Picture: Chapter One Pictures / Kevin Baker

Anyone who has been in hospital with their child for a minor emergency will have seen the other parents. The ones with the seriously ill child, who know their way around the ward, they’ve obviously spent too many hours here already. You wonder about their lives and thank whatever God you believe in that it isn’t you.

Best Interests (BBC One and BBC iPlayer) lifts the veil on these lives. It’s a gruelling, emotion grinder of a drama, with Sharon Horgan and Michael Sheen playing Nicci and Andrew, parents to Marnie, who was born with a form of muscular dystrophy that doctors believe will shorten her life considerably.

We join the action with a resolute Nicci talking to reporters on the way into court, her father and other daughter at her side, while Andrew approaches on his own — the couple obviously separated and at odds.

Best Interests is the story of how they got to this point. Sharon Horgan’s Nicci is beautifully drawn, strong, funny, embittered, and single-minded in her belief that Marnie should be kept alive for as long as possible.

Andrew is quieter, struggling to conceal the tidal wave of sadness that he faces every day. He thinks Marnie has had enough suffering and shouldn’t be treated after a cardiac arrest leaves her with brain-damage and in a coma.

Of course, they’re both right. So there is no easy vantage point for the viewer here, you have to ride the emotions along with them. Our way into the story is through that other daughter, Katie, played by Cork native Alison Oliver in her next major role after Conversations with Friends. She has backed away from the family a bit, 17 now and trying to carve out a life of her own with her girlfriend, away from all the pain.

There is no escaping the pain for Marnie, but she’s played with gusto here by Dublin actress Niamh Moriarty, so that most of the feel-good moments come from her having a laugh.

But really this is about Nicci and Andrew not being on the same page about the best way to deal with the end of Marnie’s life. There is a realness here, the calm dull suburb where they live, their home choked with the paraphernalia that comes with having a sick child, the way they know the doctors and nurses so well that they can tell one of them to eff off without causing offence.

But the drama, suffocatingly sad at times, comes from the parents. Horgan is outstanding, brimming with anger at the fight (possibly solo) she had to put up to get Marnie treated throughout her life. Her force of nature attacks on the doctors feel unfair and spot on at the same time.

Sheen occupies Andrew, playing it with an almost invisible stoop to portray how life as the parent of a sick child can chip away at your energy, forcing you toward surrender. You don’t have to take sides in this show. You can’t. But you should definitely watch it.