Joanna Vanderham has an air of sleeves-up, get-it-done practicality, spliced with mercurial beauty, winning mischief, and a deep passion for her work. However, she starts our interview by giving a really dodgy housekeeping tip – when I realised I’d got chewing gum on my skirt, she offered the following advice: “I’m sure you can iron it off. No, wait, is that wax?” She is instantly believable in all things, on screen and off, but don’t believe her on chewing gum.
In One of Us, she plays Claire, a nurse whose cherished brother has been murdered, along with his new wife. As she supports her mother and other brother – as well as the neighbours, who were parents to her dead sister-in-law – it’s plain that she is the lodestar of the group, its unwavering moral north: everyone else is either too immature or too messed up.

One of Us
So it’s a new gear in her six-year career, which started fast – her first
 job, a lead role in 2011 Sky1 drama
 The Runaway, earned her an International Emmy nomination
– and only got faster. She’s played
 the arch, high-class beauty (in Dancing on the Edge), the grafting, 
plucky beauty (in The Paradise), and
 the heroine in Banished and The Go-Between, but she hasn’t, until now,
 been the grown-up of the piece.
She gives a fascinating, big-hearted but small-gestured performance, especially in her scenes with Juliet Stevenson, who plays her mother. “At the start of filming,” she says, “I’d been thinking, ‘How do I get on with Juliet?’ And she grabbed my arm, and said, ‘I think I’ll hold on to you.’ And that was it. For three months, she held my arm. We were each other’s rock, you can see it in the episodes, when she goes to sit down, I’m right there with her.”
She makes a face that I decode as, “Does that make us sound like luvvies?” and continues: “Juliet was quite good at making sure we’d all discussed what had happened before each scene, how each of us were feeling, she created intense mini-rehearsals before each scene... but at the same time, she’s such a big child. We spent so many hours discussing how awful our jeans were.”
One of Us
And they certainly were – the least flattering denim you’ve seen on TV since Jeremy Clarkson left Top Gear. Which is part of the charm: it’s a very intense drama, with many very visually striking moments, characters making life-changing decisions, standing in a barn, lit from behind, like Reservoir Dogs.
Vanderham – born in 1991 in Scone, a village in Perthshire – takes an unstudied, unguarded delight in her work: “I have an overwhelming urge to tell stories. I don’t know why. I don’t know where it comes from.”
She has none of the blasé patina that people get when they come from a showbiz family. Her mother, a cardiovascular specialist in Dundee, “made me promise that if I hadn’t made it by the time I was 28, I would retrain. I don’t know what ‘made it’ means, in her view. And I don’t know why 28. But I wouldn’t ever want to give up.”

Whatever the mysterious criteria were, she is pretty certain to have met them. Apart from her apparently effortless TV success, she has also played Desdemona with the RSC, a performance for which she won some stunning reviews that have made apparently no dent in her self criticism. It was a daunting role.
“A 1,200-seat theatre – we started tech [rehearsals], and I walked on stage, and my throat closed up, and I started to cry. I had a little anxiety attack, which I’ve never had in my life. I’d like to do that part again. I want another go. I’ve learnt a lot since last year.”
She’s currently starring alongside Ralph Fiennes in Richard III at the Almeida Theatre in north London, as Lady Anne, who famously dies pretty early but has to come back at the end as a ghost. “There are fabulous stories about the ghosts all going to the pub, and coming back pissed. Sometimes I almost forget my cue and come up a very breathless ghost.”
Richard III
She has no career role model, as such, but will make an exception for Grace Kelly. “She acted in 11 films, won an Oscar and then married a prince. She didn’t do too badly.” I raise an eyebrow at the idea that she would give this up to marry anybody, prince or not, and she says: “This is my idea of modern feminism: men and women are not the same, we’re equal in different ways, and if that means I earn more than you but you want to open the door for me, great.”
It’s good she doesn’t want to marry someone more succesful than her, I say, as that would seriously shrink her pool. “Thanks. Wow. That is beyond depressing.” I insist that it’s a compliment, the inevitable result of having done so much so young.
“We’ll see what happens. Those thoughts have crossed my mind. But you can’t worry about it because that’s a waste of energy, isn’t it? Just as I can’t worry about the fact that you’ve just cursed me to be permanently alone.”
She has a wonderful dialectical quality to her, carefree but intense, confident enough to take risks but careful and modest. There isn’t much light nonchalance in her performance in One of Us, but her range and magnetism are becoming ever clearer.
She hates watching herself on screen: “I had to remake my showreel earlier this year, and I was going, ‘I can’t believe this was recorded. Please can this never be witnessed again.’ I got six minutes out of my six-year career and thought, ‘This’ll do.’” It’s a comically harsh and utterly wrong judgement, but fortunately, the world thinks differently.
One of Us starts on BBC1 at 9pm tonight