'Best Interests' is the Best of Television

Who and what determines someone’s quality of life? Is there a right time to stop fighting for your child? How do you know what is in their best interests? These are the questions the fabulous new series Best Interests considers with heartbreaking authenticity. Already a success in the U.K., where it debuted in 2023, the four-episode series follows Nicci (Sharon Horgan) and Andrew (Michael Sheen), whose daughter Marnie (Niamh Moriarty) was born with congenital muscular dystrophy. Nicci and Andrew’s entire life is structured around and dedicated to the care of their daughter.

The series opens with the pair returning from a rare weekend respite. They are still so crazy about each other that they briefly try to get busy in the bathroom on the train ride home. But once home, they soon realize Marnie has spiked a fever. This is not an infrequent occurrence. However, sadly, that’s the last time we see Marnie in the present-day alert. She has a severe chest infection. Plagued with guilt, Nicci worries that they would have noticed something was wrong earlier if they had been home. “You didn’t do anything wrong. You’re excellent parents,” Marnie’s doctor, Samantha (Noma Dumezweni), kindly tells them.  

Nicci and Andrew think this hospital stay will be like the others, and they will soon be able to bring Marnie, now 13, back home. But this time, it is different. Marnie’s body is deteriorating. Every time she is intubated, it damages her fragile body even more. Samantha thinks it’s time to start discussing palliative care. A furious Nicci is not ready for that discussion. “She still laughs. She still loves. I can still see so much inside her,” she says. Suddenly, the doctor who has cared for Marnie all of her life has become her adversary. Things go from bad to worse when Marnie suffers a cardiac arrest and may have brain damage. 

When Marnie is first diagnosed as a baby, a doctor tells the couple, “There are many beautiful stories in this life. Please don’t assume that Marnie’s will be any less beautiful. It will just be different, and you have to adapt to that difference. And you’ll find such joy if you do.” And flashbacks reveal that to be true. We see Marnie racing in her wheelchair, pretending to be an astronaut with her parents, dancing and goofing off with her sister Katie (Alison Oliver), and going to the movies with a boy who is smitten with her. The very nature of Marnie’s joie de vivre makes her a fully formed character, not someone to be pitied. The series may alter the way viewers see and treat people with disabilities. 

We also see the long-term effects of caring for someone who is chronically ill, how ingrained the rhythm of Marnie’s care is into their daily routine, and how much they know about their daughter’s rare disease. They have read the studies. They know about the innovative treatments being offered. They are used to constantly fighting—for treatment, for wheelchair access, for their daughter to be treated with dignity and respect. 

We also see the effects it has on the family. Nicci is more angry, feisty, and ready for a fight. Andrew is more resigned, sad, and perhaps more aware of the impending reality. Now in her last year of high school, Katie is used to not being the focus of her parents’ attention. How could she be? Her orchestra recital will never be as important as her sister’s health. As her parents get increasingly involved in what will happen to Nicci, Katie must fend for herself.

As the series progresses, organizations with names like “Every Christian Life” get involved. There are TV stories and radio interviews. The series culminates in a court case about what is in Marnie’s best interest. But the series isn’t really about all those things. Writer Jack Thorne (Joy) doesn’t offer pat solutions. Thorne makes it clear that there is no right answer here.

The series is also a chance to watch two actors at the absolute top of their game. We know Horgan can balance comedy with tragedy from series like Catastrophe and Bad Sisters. Best Interests truly showcases her dramatic chops. She brings such depth to Nicci, and Sheen matches her step by step. They are buoyed by an impressive supporting cast; Moriarty is a notable a delight. When Katie wonders, “How can you let go of someone who still laughs?” we understand exactly what she means. Oliver is equally fantastic as the teen who loves her sister but is struggling to accept all that is happening and the best way to deal with it. With quiet dignity, Dumezweni shows the toll caring for chronically ill children has on their doctors. 

Together, this amazing cast creates a series that is in your best interest to watch. 

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