Like her rebellious alter ego, Lady Rose MacClare, it seems Lily James, the actress who plays her, isn’t one for airs and graces.
She arrives for our interview mid-way through a busy day promoting the new series of Downton Abbey and by way of introduction says: “Hello, I’m really hot and sweaty.”
The 25-year-old’s honesty and openness backfired on a recent holiday in south-east Asia, however, when she let slip her day job to a boatload of fellow tourists.
“We all had a few drinks, and people say, ‘What do you do? Oh, you’re an actor, oh really, in what?’ And you’re like, ‘Umm, Downton Abbey’, and they’re like, ‘Argh!’, and you’re stranded on a boat,’” James exclaims.
“From then on, I pretended I worked in a cake shop...”
The actress had better brace herself for even more attention in the months ahead, with a lead role in Kenneth Branagh’s upcoming Cinderella film (due out next year), and a rumoured romance with former Doctor Who star Matt Smith.
But first things first, there’s a fifth series of Downton to discuss.
Surrey-born James joined the show as the Dowager Countess’ fun-loving great-niece in 2012, two years after graduating from the Guildhall School of Music and Drama.
Last year, Rose, who was taken in by the Crawleys when her parents moved abroad, threw herself into the London party scene and enjoyed a romance with jazz singer Jack Ross - only for him to call their engagement off.
In series five, we’ll see the character develop more of a social conscience, undertaking volunteer work and dabbling in some matchmaking for widowed former chauffeur, Tom Branson.
“She’s growing up a bit,” James explains. “I think after all the drama of last year - falling in love about five times, having her heart broken and then realising, actually, she’s fine - I think she’s ready to take life a bit more slowly.
“And she feels safe at Downton, which is a feeling Rose never had. She’s always felt quite unstable and unloved. Poor Rose.”
There’s still some hope of the beautiful character meeting a suitor, however.
“For girls that age, that was it - that was what you did, that was what you looked for, that was your future,” says the well-spoken actress, turning serious for a moment.
“You can’t deny that would be part of what’s going to happen for Rose in the foreseeable future. Having said that, she’s not going to settle for anything but head-over-heels love, which is hard to find.”
We’ll also see the return of Rose’s father, played by Peter Egan.
“We had the best scenes together, very moving and teary. He’s such a perfect father, and then on the other hand, she has this mother that’s so difficult,” James adds.
“You see why Rose is the way she is, because of how she’s been brought up and the tension of her family life, which escalates this year.”
James counts co-stars Michelle Dockery (Lady Mary) and Laura Carmichael (Lady Edith) as “some of my closest friends”, but admits she’s still getting used to the long periods of downtime between takes.
“I’m trying to figure out, as an actress, how you deal with that kind of boredom - of long hours and early starts and sitting around not doing anything. I find that reading is the best, because you get lost in another world, and then you can come back out fresh.”
Landing a role on the award-winning show - which has been sold to 250 territories worldwide - has been life-changing for the actress, who previously starred in the TV series Just William and the sporting drama Fast Girls.
“It’s so hard coming out of drama school to claim your right to be taken seriously, and even get auditions. Now I’m getting auditions, I know what I’m doing next, I’m so lucky and I really don’t want it to stop,” she adds with a smile.
“I’m having the best time, and I’m getting to work with people I’d never dreamed I’d work with.”
Downton Abbey, Sunday, 9pm, ITV