ONE OF the best things about going to the Toronto International Film Festival each September is what seems to be an annual interview with Keira Knightley.

From "Atonement" in 2007 through "Anna Karenina" and "A Dangerous Method," Knightley has been a festival staple and one of the best actress interviews out there.

She's friendly, good-humored and a thorough researcher of her roles. Most importantly, she's chatty. Ask her a question and you get a real answer and not a series of talking points that show up in every writer's interview.

In September, the Daily News spoke to Knightley about "The Imitation Game," in which she stars as under-appreciated math genius Joan Clarke, who helped Alan Turing (played by Benedict Cumberbatch) break the Nazi's Enigma code during WWII.

For the first time in our Toronto meetings, Knightley was a tad peeved.

"I'd just like you to know," she said, "that Benedict's room is far better than mine and he's got jelly beans.

"I'm just putting it out there.

"I'm fine about the table. I'm fine about the settee that he's got. But the jelly beans are just niggling me." (Editor's note: Before folks criticize Ms. Knightley, the word "niggling" stems from the Scandinavian and means to cause a slight annoyance. It has no racial connotations.)

When we told her there were berries in the hospitality suite, that really got her going.

"This is clearly a 'don't feed the actress' situation, isn't it?" she added, mock-haughtily.

With the food issue covered, we discussed "The Imitation Game."

Q: You love to do research for your films. How did you research something so secret?

A: There actually is a lot and I think most of it was declassified in the '90s. There is a biography of Joan that I read and then saw a couple of documentaries and then found out that, particularly with Joan, the movie's not totally accurate. So, as soon as I realized that it deviated quite a lot from the truth, I had to go with the script.

I based Joan on the notion that if you're a woman at that time in a completely male-dominated world, how do you get your own way? You do it by being nice - by nobody noticing you and people not seeing you coming. You don't do it by being a bull in a china shop.

I was very interested in the idea of Joan being "lovely." That she can be exactly what you need her to be. Nobody's going to feel she shouldn't be there. Nobody's going to be pissed off at her. She'll smooth-over everything and be quite charming. I liked the idea that she could be a bit like sunshine.

You could make a film about any of these people. When you look into them, they are fascinating. And the fact that they never spoke about Enigma - even after it was declassified - and people tried to go to the survivors and record their testimony. Even then it was very difficult to get them to speak about it. They'd locked it away.

Q: How was the real Joan different from the movie Joan?

A: It took Joan at least a year [to rise from the secretarial pool] even though she'd been recommended by a professor at Oxford [and not by Turing]. And then she wasn't paid the same as the guys. It's still the same feminist argument today: There's no place at the table and if there is, there's no equal pay.

Q: The movie is very clear about the importance of cracking the code because of the bombing toll Germany was taking on Britain. Does that still resonate with Brits of your generation?

A: For my generation, no. But as a Londoner you see the scars on the city everywhere you go. You'll be walking down a road of 18th-century buildings and all of a sudden there's a brand new office block and you think, wait a minute . . . oh, that was bombed. Anywhere in the East End. And anyone of my generation's grandparents was probably alive so you've grown up with the stories. But it doesn't feel like an emotional connection to me, it's more something of interest.

Q: One of the deepest concepts of the film is the notion of war through the eyes of a mathematician. It's human life filtered through a cost-benefit analysis.

A: Ah . . . "the greater good." That was a fascinating part of the script. Cracking the code is almost the beginning of the story of the morality of everything. Obviously what happened to Alan Turing is horrendous, but that argument of the greater good is always a very tricky one. It was only about two or three years ago that we learned about Coventry - a city in England totally annihilated, with a huge loss of life. And they knew that was going to happen and they chose not to save the city. It was absolutely shocking that they knew and yet . . . If you're completely logical you can make the argument that the greater-good argument always works. But if it was my family, if it was my husband, or me, you'd be horrified.

Q: So you kind of do need a logical sociopath to make those decisions or the war strategizing would be paralyzed?

A: Or you could argue that we need no logical sociopaths and then war wouldn't start in the first place. Then we'd all be empathetic and we'd all know that we shouldn't just go around killing each other for various reasons. And then we might have a happy world.

But given that we have logical sociopaths, you need one to fight one.