Everyone has their secrets. For most, it's a personal failing or foible they'd prefer to keep to themselves or, perhaps, something salacious about a friend. But some people hold secrets that are bigger, badder and with the potential to blow up everything they hold dear.
It's the skeleton's in these cupboards that the new psychological thriller, The Secrets She Keeps, dares to rattle. The show, based on the novel by crime writer Michael Robotham, follows two women with vastly different lives. There's Meghan, a glamorous Instagram Mummy blogger with the perfect family, children and life, and Agatha, a supermarket worker and soon-to-be solo mother. After a chance - or was it? - meeting, the pair bond over their pregnancies and so begins the entanglement of their lives.
"It's so interesting to make the threat something really feminine. You don't see that much," muses Laura Carmichael, who has swapped the elaborate and rich period costume of her Downton Abbey character, Lady Edith Crawley, for daggy hoodies and Agatha's unflattering checkout uniform.
"The drama comes out of Agatha's desire to be a mother and around Megan's need to be the perfect mother and the perfect wife and the struggles and pressures that puts on them," she explains. "That's the pressure of the story that leads to some very dark moments. It's not gun-toting crime drama, it's something that's very specifically female. I thought that was very interesting."
As well as its fresh spin on the thriller genre, what Carmichael says she really liked about this show was it's ambiguity in that it's not a tired old "hero and villain" story.
"It doesn't side with one woman over the other with one becoming a dark baddie," she says. "That was so clear in the script that they didn't want that to happen. But at the same time, it is high drama and that's something where you really have to play to the stakes of it."
As an enthusiast of the genre, Carmichael says she was thrilled to finally star in a thriller.
"I'm always drawn into them. They're completely absorbing when they're at their best. I remember watching The Killing when it first came out all those years ago and I didn't leave the house for a week, I was so completely absorbed," she says, grinning. "I took it very personally, like I was the one working and needed to find the killer before I left the house. I'd see friends on the weekend and go, 'I've been involved in a murder case I'm afraid, that's why I've not been around."
The Secrets She Keeps dives into the facade of Instagram and the myth of the perfect lives that everyone presents on the social platform. It has to be said that Carmichael's own Instagram is extremely glam, filled as it is with an abundance of stunning red-carpet appearances, swanky showbiz parties and glitzy magazine covers.
Does she ever feel those pangs of jealously or envy as she sits there scrolling through other people's instagram lives?
"Sure! Yeah, totally," she says laughing. "It's part of that culture, what we're all led to do now. To put out a perfect version of yourself that we know is not really true. That's something that we all live with."
It's crazy how we all know it's false yet we all still fall for it, Why?
"It's true," she says. "I don't know. I guess it's in human nature. Those pressures have always been there but it feels as if they're ramped up because the way we share information about our lives is that much more complicated now."
Carmichael's been a delight, friendly, funny and super chatty, so I decide to press my luck. What, I ask, would be a secret that she keeps?
"Oooo . . . excellent question!" she exclaims with a grin. After ticking it over for a second she confesses, "I'm such an open book. I'm the worst liar. I completely am a person who feels like I need to share all of my secrets. So, it'd probably be more like a guilty pleasure."
Okay, hit me.
"I watch a lot of TV. I'm not without it. Anything basic you can think of, I watch it," she says. "Probably things people wouldn't expect."
Like?, I prod.
Knowing her secret is now out of the bag she explodes in laughter and answers.
"Trash."
LOWDOWN
Who: Laura Carmichael
What: New psychological thriller The Secrets She Keeps
When: Now streaming on TVNZ OnDemand