Evilness aside, the witchy voluptuousness of some of Bonham Carter’s on-screen characters is not dissimilar from her infamously whimsical off-screen style. Her fondness for dressing in eccentric, multilayered ensembles has for years landed her on both best- and worst-dressed lists. As a nominee for best actress at the 2011 Golden Globes for her work in The King’s Speech, Bonham Carter walked the red carpet wearing a low-cut Vivienne Westwood number in tulle-covered floral accessorized with different shoes: one red and the other green. Predictably, this kind of irreverent move had its share of detractors, but it was precisely its devil-may-care zaniness that inspired Marc Jacobs to ask her to be the face of his Fall 2011 ad campaign.

Bonham Carter’s latest collaboration with Burton is the new film Dark Shadows. Due out this month, it is based on the late 1960s Gothic soap opera of the same name, and tells the story of a 200-year-old vampire (played by another Burton regular, Johnny Depp) who returns home to descendents so deeply troubled that they have invited a psychiatrist with a drinking problem (Bonham Carter) to live with them.

Whether she’s playing an English rose or a sadomasochistic witch, Bonham Carter has never ceased to be interesting-as her Harry Potter costar, Daniel Radcliffe, well knows. Radcliffe visited with the 45-year-old Bonham Carter at one of the two homes she shares with Burton and their two children in London.

DANIEL RADCLIFFE: You have quite an overachieving family.

HELENA BONHAM CARTER: Do you think so?

RADCLIFFE: Well, you’re descended from a prime minister, several politicians, and a very influential director. And your maternal granddad was a Spanish diplomat who was awarded the Righteous Among the Nations a few years ago, which is amazing. And your mother is a psychotherapist.

BONHAM CARTER: Wow. You know more than I do.

RADCLIFFE: But that intellectual milieu—how did that launch you? Because you did start young.

BONHAM CARTER: It was nothing to do with where I came from, in the sense that mum and dad never brought us up with any kind of pressure. There weren’t any expectations, which was great. But I was incredibly self-critical and very driven. Thank god I got slightly less self-critical as I got older.

RADCLIFFE: Have you then? Does that go slightly?

BONHAM CARTER: Oh yes. Don’t worry. It’s so much better when you get older.

RADCLIFFE: Oh, thank god.

BONHAM CARTER: I think you physically fall apart. But mentally, it’s so much easier.

RADCLIFFE: I certainly suffer from a slight inferiority complex when I step into a room of other actors because I’ve never trained, and I know you haven’t either.

BONHAM CARTER: Oh, I had a big inferiority complex till yesterday.

RADCLIFFE: But not today!

BONHAM CARTER: Everybody has an inferiority complex when they step into a room. But then when you have children and you get older, it doesn’t really matter. When I was young I had so many inferiority complexes. I had an inferiority complex because I didn’t go to university. I had an inferiority complex because I didn’t train. Then it gets tiring. And you do get bored of it.