Keira Knightly talks on the Imitation Game and unconventional love

Keira Knightly discusses World War II drama The Imitation Game, which tells the real-life story of the mathematician and computing pioneer Alan Turing.

Keira Knightley, left and Benedict Cumberbatch appear in a scene from The Imitation Game. AP

"The Imitation Game isn't really a conventional romance," says Keira Knightley. "It's something quite different." That is quite the understatement. The World War II drama, which is screening at the Dubai International Film Festival, tells the real-life story of the mathematician and computing pioneer Alan Turing (played by Benedict Cumberbatch) who worked at the Government Code and Cypher School at Betchley Park, Britain's code-breaking centre that was assigned the task of cracking German war codes.

The drama portrays Turing as socially awkward and slightly autistic – but a genius at solving puzzles. Bending history, it shows him at odds with his co-workers as he tries to convince them that his methods will yield results.

During that time, and true to the real-life story, he met and became engaged to cryptanalyst Joan Clarke, played by Knightley. It was an unusual relationship in many ways, not least because Turing was homosexual (and was jailed as a result in 1952) and also that Clarke wanted to go through with the marriage even after he told her.

It’s the kind of awkward situation that Knightley says she has always admired in her favourite romances.

"I think that we are in a period where romantic comedies feature perfectly polished, plastic cut-outs of people and that is not what I like to watch," she says. "When you go back to When Harry Met Sally, that kind of era, they weren't perfect. They're more like these sort of characters – they were having problems."

Apart from Lynn Shelton's Laggies (retitled Say When for its UK release), Knightley's most recent romantic roles haven't had a particularly happy ending. In Begin Again (also known as Can A Song Save Your Life), she has a doomed tryst with a record producer played by Mark Ruffalo. She also played the doomed Anna Karenina.

These difficult on-screen romances have played out while the actress has been enjoying marital bliss in real life, after tying the knot with Klaxons keyboard player James Righton in May last year.

In The Imitation Game, Knightley uses the character of Clarke to represent the changing position of women in society. She's confident, intelligent, socially adept and full of confidence.

Knightley – with her cropped hair and zesty manner – is well-cast again, just as she was the tomboy footballer in her breakthrough film Bend It Like Beckham, and as the feisty heroine Elizabeth Swann in the Pirates of the Caribbean movies.

Some have criticised The Imitation Game, because it deviates quite a bit from the more mundane truth. Knightley acknowledges that there was a degree of artistic license.

“There have been liberties taken. It’s a drama, not a documentary,” she says. “Joan Clarke died in her 90s, and quite a bit of her story has been altered somewhat from the truth. So you have to go, ‘We’re going for this story, that is in the script’. It was slightly different.”

Knightley has said that she often has to play second fiddle in films because there are few scripts about female geniuses being written. In the upcoming Everest, for example, she was on set for only five days in her role as the wife of Rob Hall, who died while attempting to climb the world’s tallest mountain in 1996.

Yet despite her concerns, the London-born actress seems to have reached an inner peace about her career.

“I found that after 25, everything has been great,” she says. “I don’t know why. They say that until you’re 25 your brain is unwiring. Maybe that’s it. Maybe that’s what happens after 25. It’s just slow unwiring. And that’s all great.”

• The Imitation Game plays on Tuesday, December 16 at 6pm at Madinat Arena and on Wednesday, December 17 at 6:15 p.m. at Mall of the Emirates Cinema 11.