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In general, it seems as though the roles you take tend toward extremes: either way out there or very demure.
It depends on what comes through, really. Writers and directors often have a far better idea of what I'd be able to do than I do. When I did Iris , I tried to persuade Richard Eyre that I was completely wrong for the part [of John Bayley], but he persevered.
It seems your character in The Iron Lady, Denis Thatcher, fits into the latter category.
In the film, Denis doesn't have a straightforward, biopic-type role. The character appears more in [his wife Margaret's] dreams or fantasies. That was a challenge in itself—to play a role where you're not trying to work out your motivation because what your character is doing comes from someone else's mind. It changes the rules somewhat.
Did you find anything frustrating about that approach?
Not really. There's very little known about him really. He did one extended television interview with his daughter, Carol, and she wrote a biography of him. Otherwise, he was very private.
What made you want to act in the first place?
I always liked the idea of acting, and my parents were part of an amateur theater group, which is how I got cast in A Doll's House at age five. When I was leaving school, I was either going to pursue art or drama.
Speaking of art, I hear you enjoy sculpting gargoyles.
Not so much gargoyles now, but other figures. It's another way of making characters, I think. I carve the heads, put them on bodies and clothe them. They're only about three feet high. I get hair from the wig department's unwanted wigs.
How did that become a hobby?
I'd been given some woodcarving chisels as a teenager, which I hadn't really used. When I was in my thirties, I got them out of my trunk and started playing with them again.
Where do your ideas come from?
My imagination, really. I follow an idea to see what character emerges, but then I have various books of photographs and art books that I can look at to make sure I'm getting the physiology right.
One of your most famous characters, Professor Slughorn from Harry Potter, was known for "collecting" bright, talented students. Have you amassed any collections of your own?
I do have a bizarre collection of model John Deere tractors. Growing up in the country, there were one or two of them around the farms and something about them strikes a chord. I've gathered together twenty or so.
If you could choose your next role, what would you pick?
I've never had a list of people—[you have to be] careful of what you wish for.
The Iron Lady opens Jan 13.