My husband Rhashan reminds me of my father because he's got great strength of character.

My agents were like "Come to L.A., we've got meetings for you." I was like "No, I'm doing this now." Then my father became very ill back in England, and I didn't want to be away. I went back to England and did a bunch of crazy indie movies, all of which I loved with a passion, and none of which did any business.

My parents are both lawyers, and my father always said his best cases have been returns, cases that come into his office from another lawyer. So he said, "Never be ashamed to take a return." All my best roles have happened because someone else dropped out at the last minute, and God bless those actresses for their queeny fits, their sprained ankles, their better job turning up, because that's how I've got my best work.

I was lucky, because Ewan McGregor had already been shooting with Roman Polanski for about a month before I got role. And he did a faultless impersonation of what it was going to be like. So when direction happened, it was like, "Oh yeah. That's what Ewan said was going to happen." And so it was a little bit less debilitating than it might have been.

Joss Whedon writes beautiful drama. His sensitivity and his sense of drama and scenes are pretty exceptional. There's no one else writing like him, really, in sci-fi and TV. That's not to say there are no astonishing writers on TV. I was nervous about coming to America and playing an English person who speaks very English when all the writers are American, because it's a very particular thing to imitate, and if it's badly imitated, it sounds painfully contorted and silly. And he writes very well for English people. It was Joss Whedon who persuaded me.

Ewan McGregor is a very genial and entertaining man, and Pierce Brosnan is possibly the nicest man in the world. Actually, it was quite a genial set The Ghost Writer, but the weather and the colors and the actual surroundings were oppressive. But it was a created atmosphere. What was so striking is that Roman Polanski had his crew from The Pianist, and we were shooting in Berlin, so there were German and Polish and French people, and I was just sort of enjoying being in this mix of people, all kind of rubbing along together. That felt good.

Ewan McGregor and I said this to each other after we saw The Ghost Writer. Every time Roman Polanski did a "No, no, no!," he was right. It was really as if a sculptor was asked to sculpt the embodiment of despair - that was the attitude he would strike. But as with every sort of inspiring teacher you ever had who was strict and scary, when you get it right, the sun comes out, and it's worth it.