A love triangle will always reel me in, but a love triangle in the world of Agatha Christie? The intrigue was tenfold. Towards Zero, the latest BBC adaptation of a Christie novel, sees British tennis star Nevile Strange (Oliver Jackson-Cohen) go through a very public divorce with his ex-wife, Audrey (Ella Lily Hyland), before marrying his new wife, Kay (Mimi Keene).

A celebrity divorce is already messy enough, but the trio then find themselves all under the same roof at Nevile’s childhood home at Gull’s Point. These strained relationships and the unfinished business running through them provide enough chaos for one summer, but throw in a matriarch, a long-suffering lady’s companion, a mysterious gentleman’s valet, an exiled cousin with a grudge, a venerable family lawyer, an inquisitive orphan and a French conman, and you’ve got a recipe for murder.

For me, the most interesting dynamic in the series is between Audrey and Kay. Nevile may be the sticking point between the two women, but the real obsession is between them, and Nevile becomes a mere byproduct of the love triangle. “He wouldn’t exist without them, but it’s also Audrey and Kay attempting to find or regain their power in what seems like a powerless situation. But it’s the both of us who are the ones with the power, not Nevile,” Hyland tells Stylist.

Audrey has known Nevile since she was 11 years old, and the pair grew up together and ended up forming an intense bond in their teenage years. As Nevile’s fame and status in the tennis world grows, Audrey ends up in the spotlight too and adopts a similar winner-led mentality, but this competitiveness seeps into their own life and relationship, and their love becomes a never-ending game. It’s almost as if Audrey is a part of him and doesn’t exist on her own.

“A lot of their relationship is based on this skewed power dynamic, where they’re both trying to one-up each other all the time. When Kay enters the picture, Audrey ultimately brings her into this game that they’ve been playing since they were kids,” says Hyland.

Initially, Kay is an outsider to Nevile and Audrey’s world. She is unaware of the warped and game-like dynamic she’s found herself a part of (her initial motives for marrying Nevile are revealed later on in the series) and can’t quite understand why Nevile can’t leave Audrey alone. She views Audrey as the outsider in their marriage but soon realises that maybe it’s she who remains the outsider, especially after spending a couple of days at Gull’s Point. “A lot of Kay’s thinking is around Audrey, and why this woman refuses to be ashamed or embarrassed that she’s hanging out with her ex-husband and his new wife. It baffles Kay,” explains Keene.

As the series goes on, we learn more about Kay and why she makes the choices that she makes. “She’s not very proud of her upbringing or background, and it’s turned her into an opportunistic person. But a very modern woman for that time period, especially in how outwardly confident she is. From the way she talks to the way she dresses, Kay commands attention and wants to be seen and heard in every room she’s in,” says Keene.

It’s what the actor loved about the character and made her a lot of fun to play. “I do feel she stands out in a way that wasn’t the done thing at the time and I love that about Kay.”

Hyland also admires this about Kay and explains how Audrey is a very different kind of woman who is likely intimidated by Kay’s confidence and modernity. “For Audrey, it’s almost a jealousy of Kay’s perceived freedom and independence and perhaps even an element of lust for a life that you desire. It’s similar to that feeling you get when you’re not sure if you want to be her or be with her,” says Hyland.

And here’s one particular scene that both actors loved a great deal that really highlights this dynamic between the two women and it’s a dancing sequence during one of their evenings at Gull’s Point. Kay is the type of person to put on a record and just get up and dance in a room full of people, but Audrey is much more controlled – even if she wanted to dance, she wouldn’t because of what people may think of her.

But when Kay offers her hand to Audrey and invites her to dance with her, there’s a brief will-they-won’t-they moment before Audrey does choose to dance with her ex-husband’s wife. “It’s always interesting to have your character do something that just isn’t part of their personality, that the viewer wouldn’t imagine her doing,” adds Hyland. The dancing scene is such a brilliant depiction of Kay realising she’s part of Nevile and Audrey’s strange little game and deciding to play too. “Do they hate each other? Are they going to fight? Or will they kiss instead? This scene is the epitome of the relationship between the two of them,” says Keene.

As well as the gripping murder mystery storyline, it’s the complicated relationship between these two women that really makes the show what it is. The cold stares, the quick sharp looks over the shoulder and the cutting quips between Audrey and Kay not only make for brilliant and dramatic television, but they also centre the wants and needs of women at a time when these things were rarely taken into consideration.

Agatha Christie’s Towards Zero will be available in full on BBC iPlayer from 6am on Sunday 2 March, with episodes airing weekly on BBC One from 9pm that night.

Images: BBC