Karen Gillan's powers extend beyond being able to thwart aliens and grapple with the theories of time travel. She is an idol to teenage girls, an object of desire to male Whovians and an exemplary fashion muse, courted by designers and the makers of luxury handbags, and con-sidered only marginally less influential than fellow celebrity clotheshorses Alexa Chung and the Duchess of Cambridge.
That Karen has entered the national consciousness so completely seems astonishing when you consider that only two years ago she was an unknown actress from Inverness, working in a South London pub and doing a spot of modelling to subsidise her career. But then Steven Moffat came knocking and selected her to be Matt Smith's companion, Amy Pond, in his rebootedDoctor Who. Her first appearance, as a police officer kissogram dressed in the shortest skirt the Tardis has ever witnessed, ensured her life would never be the same again.
Karen, who at 23 is the same age as her on-screen alter ego, happily takes full responsibility for the skirt that sent so many sci-fi fans into an interdimensional spin. 'They kept trying to put me in various denim ensembles. And I was like, "No, no, no. It has to be a short skirt, because that is what girls my age wear." And when I wore that skirt, I felt like Amy.' As if to prove a point, today she is wearing an equally short black Lycra mini and a pink woollen jumper sewn with tiny pearls, booty from one of her many trips to the vintage clothing emporia of Brick Lane. 'Amy is basically the person I want to be,' she explains. 'I just don't have her sassy attitude. But I like that about her, and I like that about other people. I am attracted to people who are mouthy and brave and adventurous.'
She may not be brave and adventurous, squealing and running away when a wasp hovers over her Caesar salad, but Karen is wildly beautiful, with wide, surprised eyes, a heart-shaped face, acres of auburn hair and milky pale skin. As such she seems a clever choice to play the queen of gamine beauties, the model Jean Shrimpton, in the forthcoming BBC drama We'll Take Manhattan, about Shrimpton's 1960s ascendancy and her relationship with the cocky Cockney photographer David Bailey. For Karen, it was a dream role. 'If I could go back to any period in history it would be the Sixties. Young people were so powerful.' She is also about to tackle her first theatre role, in John Osborne's 1960s play Inadmissible Evidence at the Donmar Warehouse, playing a put-upon secretary to Douglas Hodge's disaffected divorce lawyer: 'Forty per cent of me is terrified, the other 60 per cent is really looking forward to it.'
Karen has always been nerve-racked by the prospect of performance. An only child, she was raised by her mother Marie, a science-fiction fan, and her father John, a care-home manager, who taught his daughter chess and took her to charity shops every weekend hunting for classic vinyl, instiling in her a passion for Elvis Presley and Nina Simone. John is a seasoned pub open-mic performer ('like karaoke, but a bit more serious') and Karen, who was not academic, initially considered a career as a musician. 'I played the piano from a really young age and I was thinking about doing something with performance and music, and that introduced me to acting. I had always struggled with nerves so it was quite difficult for me.' She left home at 16 to go to drama school in Edinburgh, and came to London aged 17, living on the Old Kent Road with a group of fellow drama students and studying at the Italia Conti school until she dropped out for a role in an episode of ITV's Scottish detective series Rebus. A couple of fallow years followed and then came Doctor Who and the universal adulation, the intensive filming schedules in Cardiff and the merchandise - Karen's new flat in Kennington is filled with Amy Pond dolls, still in their original packaging.
The second half of the latest series of Doctor Who has just started and sees Amy coming to terms with the revelation that River Song, played with sexy relish by Alex Kingston, is actually her daughter, something Karen was understandably 'shell-shocked' to discover. She is signed up for another series after this one, which will please the serious fans, who have generally been reduced to a state of abject adoration by Karen's performance, although there was some dismay at the hint of romantic attraction between the Doctor and his companion (Whovians just cannot conceive of a Doctor with those sort of urges).
As in the show, in real life Karen and Matt Smith are great friends, going to gigs together in Camden and hanging out in each other's Cardiff hotel rooms in the evenings, eating hummus and oat cakes, watching YouTube and getting up to mischief, even though both have partners - Matt is going out with the model Daisy Lowe and Karen has been with the photographer Patrick Green and his tortoise Brian for over five years. 'Matt and I do stay in character a lot when we're filming, without even realising it. The lines blur; the way we interact in real life is sometimes a lot like the way we interact in the show. To be honest, a lot of the time we act like lunatics, dancing, keeping the energy up. The show is high-octane, and I am quite hyper anyway.' As with all intense collaborative efforts, it sounds like the Doctor Who team play as hard as they work (the schedule is 11 days' filming out of every 14) and stories of high jinks have leaked out, such as the night when Karen was discovered drunk and naked in the hallway of a New York hotel. She giggles when asked about this, but will not elaborate.
Back home in London, she likes to spend her weekends shopping for vintage clothes. 'It's one of my favourite hobbies. I start at the top of Brick Lane and work my way down and I always have an outfit by the time I get to the bottom.' On Saturday evenings she goes to gigs and 'talks to randoms'. Her favourite new bands are Mother Mother and Everything Everything. She loves antiques, esoterica and the gothic. Her favourite film isWhat Ever Happened to Baby Jane? and she would like to play Lady Macbeth, 'also from Inverness', and Elizabeth Bathory, a 16th-century Hungarian countess: 'She was like a vampire, she killed people.'
Despite Karen's almost childish charm - during the ES shoot she skips and whoops for no apparent reason andughs girlishly when asked a question she doesn't want to answer - she possesses a dark, Miss Havisham sensibility. Her favourite episode from last season's Doctor Who was the one written by the novelist Neil Gaiman, in which the team visit a shadowy, liminal planet whose inhabitants subsist on second-hand possessions and body parts. She loves anything old, hates anything new and wears a cross handed down by her paternal grandmother, a singer who never pursued her passion professionally and was a great inspiration to her granddaughter. She died long before Karen became Amy Pond. 'She was the one who gave me the determination to do all this; in a weird way I am living out her dreams.' ES