Dr Who? Gillan says goodbye to the Time Lord

It was one of those unavoidable kinks in the space-time continuum, and no amount of tinkering with a screwdriver, sonic or otherwise, could fix it. Karen Gillan had suddenly beamed on to planet Earth (well, Carnaby Street, in central London) from a distant galaxy (OK, Inverness in the Highlands). There was talk of an imminent and long-term self-imposed exile to an inhospitable alien landscape where human life forms have been known to take on strange new shapes (that is, she's relocating to Los Angeles).

Thus, she was immediately available for interview – just at the point where the school holidays had gone all Tardis-like and seemed much bigger from the inside.

To wit: I had a childcare crunch, and had no option but to make like a Time Lord and call on the help of a redoubtable and willing female assistant. In other words, I turned my 10-year-old into a redoubtable female assistant and brought her along to meet the actress who, next weekend, makes her swansong as Doctor Who's estimable companion.

Accordingly, I thought I'd let my child speak for the nationwide raging enthusiasm for this titan of Saturday- night telly, and have first stab at talking to one of the heroines du pop-cultural jour.

And, demonstrating the flaming copper-top enthusiasm that has made her a hit on Whovian message-boards, at fan conventions, and on telly for the past two-and-a-half years – and also demonstrating a honking, toothy laugh that was perhaps less well-known – Gillan took to the task like an Ood to lightbulbs.

She is, readers might be reassured to know, great with kids. She might be newly single, currently homeless and in fact devoid of most material possessions. But come the day when Gillan is maternally inclined, she'll be a natural mum. Perhaps because she radiates megawatt childlike enthusiasm herself. Little wonder, perhaps, that, with three series under her belt, she's been the longest-lasting companion of the show's modern era, beating Billie Piper, Freema Agyeman and Catherine Tate.

So, folding her leggy legs into a dark corner of a deserted cabaret-cum-freakshow club, the 24-year-old better known as Amy Pond eagerly took a couple of opening questions from a young fan.

In Doctor Who, Amy's quite feisty – are you as feisty?

"I've got to be honest – I don't think that I'm quite as feisty as the character. So that's why it's really fun doing the programme, because I get to be this person that I sort of wish I could be like, hah hah! Amy's what I would like to be like in real life. But I'm a bit more scared of things than she is, generally."

Some of the episodes are really scary – do you get scared when you're filming them?

"Sometimes I genuinely get really, really scared. Do you know the monsters the Weeping Angels? Well they freak me out so much, cos they're just like, Aaarrrgh. They're so freaky, aren't they? And they're coming back in the new series, in a big way. They're actually in the last episode I'm gonna be in. So that was really scary."

Profusely thanking my pretty young assistant, I promptly beam her to a far-off planet, a deserted former mining colony with a mysteriously pulsating core that's been sending out SOS signals for millennia. Well, to a sweetshop round the corner.

We are talking in mid-August. The premier of season seven of the new-era Doctor Who is a couple of weeks away. The departure of Amy Pond, and of her screen husband Rory (played by Arthur Darvill), is due to happen four weeks after that, in the fifth and final episode of this opening instalment of the latest series.

Episode six is being broadcast at Christmas, and will introduce the new lady sidekick brought in by executive producer Steven Moffat to console and re-energise both Matt Smith – the 11th Doctor – and the hit drama's huge fanbase. She's Jenna-Louise Coleman, best known, perhaps, as Jasmine Thomas in Emmerdale and last seen going down with Julian Fellowes' Titanic on ITV in the spring.

As regular Who-viewers may have spotted, Moffat has tweaked the new series. Perhaps mindful of the criticisms levelled at the show after the departure of previous showrunner Russell T Davies – Doctor Who became a bit complicated, even for grown-ups (or was that just me?) – this time round the telly exec instructed his writers to craft big, bold, stand-alone episodes.

"Amy and Rory are in a really interesting place in their relationship," says Gillan of the screen earthling couple whose sleepy village life was turned on its head by the Man from Gallifrey. "Over the first four episodes they resolve that, so they're in quite a good place by that point, and they'll have been on some serious adventures. Because, basically, they're five movie-scale, epic episodes," she says eagerly, nudging any catch-up viewers to get busy with the iPlayer sharpish. "And they're all stand-alone stories but they're all leading up to this departure."

The hugely popular Gillan's leaving Doctor Who has been reported as a "mutual decision". How so?

"I honestly wanted to go on my gut instinct with the whole leaving thing, and I just had a rough idea of when would be a good time for me to go cos I wanted to go on a high. I didn't want to stay in it too long and outstay my welcome. And I wanted to take the character as far as possible before it started getting a little tired."

Gillan says she approached Moffat during the filming of her second series, around 2010, and told him when she thought would be the most opportune moment for her character to depart.

"So I've known for so long – it's just this massive relief now that I can actually talk about it."

She and Moffat went for a "lovely dinner" and he took her comments on board. He filled her in on what he still wanted to do with Doctor Who, story-wise. Then, later, he came back to her with suggestions of when and how Amy Pond might head to the great black hole in the galactic skies. (No-Spoiler Alert: I'm not suggesting that Pond dies…) (Or am I?)

"So," she concludes, "it was completely mutual, which was lovely, cos then I didn't have to sit through an awful meeting where I'm getting told I'm going!"

Again Gillan's laugh explodes from her mouth. It's a marvellous, charming, expressive, uninhibited bray, her nose wrinkling and her top teeth jutting over her bottom teeth. It is, whisper it, a bit goofy.

And it's a long way from the cool beauty that gave her a modelling career before she broke into acting. And from the statuesque chic that has made her a regular in glossy fashion magazines since her Doctor Who debut in 2010. Those pins, showcased to memorable effect (and to some Middle England consternation) via the mini-skirted costume of a sexy policewoman in her first episode, have served her well.

Anyway, she knew when enough was enough. Filming Doctor Who occupies nine months of the year, with Gillan and Smith bunkered in Wales – Cardiff being production HQ – for most of the time.

"It just completely consumes your entire life," she says of a show that, since it's revival seven years ago (with Christopher Eccleston and Billie Piper in the key roles), has become a flagship of BBC programming and a powerhouse British production internationally, notably in the US. "You eat, sleep and breathe it – and I'm not k exaggerating. It's just all day, every day. So, yeah, it's a demanding job. But I feel like, because I didn't go to drama school, it's been my three years of training. I feel I can go and do anything now. It's been a really intense, amazing experience. I'm so lucky I got to go through that.

"As an actress, Amy Pond has been the most amazing character to play," she affirms. "But I still want to go and do different things. So that was on my mind as well."

Karen Gillan came to London aged 17 to follow her acting dreams. She tried her hand at bar work and modelling before being cast as Amy Pond by fellow Scot Moffat in his first season in charge. It was a big change from her home life. She was born and raised in Inverness, an only child. It's a fairly quiet town – not many rock and pop tours, for example, came through the urban heart of the Scottish Highlands.

"I basically didn't get to see many bands growing up. We didn't really get the chance. The only people I saw were Blazin' Squad! Remember them? Hah hah hah! It was one of the biggest things to happen to Inverness."

Deprived of pop excitement, teenage Gillan got her buzz from "local theatre groups and stuff". But it's to her eternal regret that she never made it to see her pre- adolescent faves the Spice Girls in concert. Although, having just seen them perform at the Closing Ceremony of the Olympics, today she's on a high.

"I was really emotional!" she gushes. "I couldn't wait! I was sitting on the edge of my seat until they came on, shouting at everyone else, 'You're not the Spice Girls, get off!' Then finally they came on and it was one of the best moments of my life."

Posh, I venture, didn't look so comfortable.

"But she never did! But I think that kind of works for her. She fills that role in the band. They are just still a totally reliable bunch of girls, going wohaaah," blares Gillan in an approximation of late-thirtysomething millionairess Girl Power. "Which I just love. It's just a perfect formula. I'm glad that I watched it cos it just brought it all back. Just seeing Geri Haliwell really going for it – she's got fire behind her eyes!

"It doesn't even matter what people do on stage for me sometimes," she reflects, possibly referring to her own profession, too, and possibly remembering her own, brief foray on stage, in one big scene in John Osborne's Inadmissible Evidence at London's Donmar Warehouse last year. "If they've got that fire going on behind their eyes, I'm just totally mesmerised."

Something my daughter had been mesmerised by earlier that day: Gillan's performance as Jean Shrimpton in the Shrimpton/David Bailey biopic We'll Take Manhattan. In the TV film broadcast on BBC4 earlier this year, Gillan played the gawky English model "discovered" by the roguish Cockney photographer in 1960. Together they revolutionised the fashion industry.

I, meanwhile, was less than mesmerised by the film's depiction of sex-mad Bailey going at it hammer'*'balls with a posho behind the scenes on a photoshoot. But luckily I managed to avert my daughter's eyes and distract her with talk of how, after three years of fleeing monsters and battling aliens, Gillan was very convincing at playing The Shrimp in her gawky teen years.

Gillan says now that she simply recalled her own brief period modelling – those times she'd felt awkward and out of her depth and unsure of how to pose.

"I don't know if I even have learnt how to do that now," she claims with a shrug. "But I feel more comfortable, that's for sure. So yeah, I completely related to the character in terms of what it feels like to be talked about but not to – which is a really weird sensation – and just everyone staring at you!"

At the time of our meeting Gillan has just finished shooting a romcom in Glasgow, Not Another Happy Ending (she plays a successful author suffering from writer's block). The director is John McKay, who also directed We'll Take Manhattan. She's brimming with enthusiasm for her time working in the city, and sings the praises of her handsome French co-star Stanley Weber.

Indeed, a few days later, the Daily Mail will insinuate – via a huge and fragrant front-page portrait of the actress, then another photograph inside of the pair attending a Celtic match – that she has "fallen" for her co-star. But certainly at our interview, she insists that her relationship with her photographer boyfriend is at an end, and that she's single. She is also without a home, having given up her flat in Kennington, south London. Her few possessions are in storage. So what, actually, has her Doctor Who fortune bought her?

"Not really anything," she happily declares. "Just some clothes. And that's really it. I spend all my money on taxis and good food. That's all I want in life. If I could have that for the rest of my life, I'd be happy," she fibs.

In fact, for whatever reason, she's hankering after her time in Glasgow.

"I haven't laughed that much in a while," she says of her period filming in the city. "Because of the people and their sense of humour. I was like, yeah, this is what it's like. I'd forgotten, a little bit. So yeah, I think I'll definitely end up in Glasgow. But I think I should do LA for a while, while I have no ties."

As of a week tomorrow, two days after she exits, stage-left, the Doctor Who universe, Karen Gillan will be in Alabama. She's making a supernatural thriller called Oculus, about a mirror with strange powers. She plays an auctioneer ("I thought it'd be interesting how she talks and stuff") investigating, alongside her brother, the mysterious death of their parents.

Immediately after that, she's LA-bound. Is she planning on basing herself there because she's in hot pursuit of Hollywood opportunities? "Good-quality movies would be the goal for me," she demurs, "things that I feel passionate about. I don't believe in working for the sake of working. I'd rather not work than do bad stuff."

But before all that, there's the matter of her other leave-taking. Karen Gillan's Doctor Who finale was largely shot in New York. She can't say much about the specifics of her departure, other than that there were crowds of screaming fans swarming the Central Park set.

"We weren't prepared for it – there was no security or anything – and it was like being in some sort of band!" she marvels. "Running to the car and people chasing us. I filmed some of it on my phone. I'm sort of aware that I'll never experience something on that level again, where people are that passionate. So I just really enjoyed it."

Was filming the climactic scenes emotional?

"Yeah," she nods soberly. "I didn't hold it together for the full two weeks that we were shooting that episode – I was crying at anything – anything! – not even sad things. So when it came to shoot the final scenes, everything that's on the screen is real!" Real tears and real snot? "Yeah!" honks Gillan, "it's not very glamorous."

After her Glasgow filming and before this London stopover, Karen Gillan popped north to see her mum and dad, and to get her washing done. "Yeah, exactly!" she laughs. "I actually did do that."

While at home for her overnight stay Gillan slept in her old room, in her old single bed, with her old decorations still on the walls and ceiling. "It's just a really funny thought having all these crazy experiences on Doctor Who, then always seeming to end up back in my old childhood bedroom, with my childhood posters – a Muse one, from when I was like an angsty teen. And I've got a Daniel O'Donnell calendar which I thought would be really funny when I was younger, from 2004 or something. And then there's loads of theatre programmes all over the ceiling, but my mum's ripped a lot of them off, so it's all little ragged edges and pins. All my Barbies have been put in the loft, though," she reveals with a just a hint of melancholy.

"But I lie there and I am like, has all that just really happened? Or did I just imagine it?"

Karen Gillan's final 'Doctor Who' is on Saturday night