The star discusses taking on his first musical, ending his final ''Potter'' film, and what's next

By Jeff Jensen
Updated December 09, 2011 at 05:00 AM EST

You bared your soul and more in Equus, but you’d never done musical theater. What made you think you could handle How to Succeed in Business Without Really Trying?
When it becomes clear to me that something is going to be really hard work, there’s a voice inside my head that says, ”You shouldn’t probably do this, because you probably can’t do this” — but there’s another, much louder voice that becomes bullying and belligerent and wants to prove that other voice wrong.

Were singing and dancing things the voice said you couldn’t do?
When I first met with the director, I said, ”The singing I’ve been working on for a while. But you won’t get me to dance. Please erase any idea of that happening from your mind.” He said, ”We have a year — let’s see what you can do then.” And it turns out you can do quite a lot if you just put the hours in. But it was 11 months of nonstop fear, 11 months of ”Oh, God, I’m still not good at this.” I say this with no false modesty: I come off stage every night and still go, ”I can’t believe I did that.”

When we spoke last, you had not yet seen Harry Potter and the Deathly Hallows—Part 2. Are you satisfied with your performance?
Well, I’m not ever satisfied. The sequence in the Forbidden Forest — when Harry meets with the spirits of his mother and father and other loved ones before confronting Voldemort — was a moment I was really worried about. It was neither as bad as I feared it would be nor as good as I wanted it to be. Put it this way: It was the most proud I’ve been of my work in a Potter movie since the fifth film [The Order of the Phoenix]. The sixth film [The Half-Blood Prince] was frustrating. I felt I had made no progression. Which is bizarre. I had done Equus between films 5 and 6 and I felt like I had come back a better actor. But it didn’t happen. I don’t know why. I felt like I was back on track with film 7. Regardless, people like the film, and I have to let go of it.

Do you harbor dreams of Hallows—Part 2 contending for Best Picture?
Yes, I do. I really think the movie is good enough to get recognition. And I think Alan Rickman deserves recognition because I don’t think there is going to be another performance from an actor in a supporting role that is so powerful, where the actor had the challenge of realizing a scene that’s been realized millions of times the world over in the imaginations of the readers. That scene — those revelations about Snape’s past — represented maybe the most anticipated part of the most anticipated movie of the past 10 years, and I think Alan does amazing, amazing work.

Your next movie, The Woman in Black, is based on a very cool, creepy novel. Can anything really scare you after Voldemort?
I mean, if the question is, Can anything scare you after being beaten up by Ralph Fiennes? — then no, not really. That was one of the most genuinely intimidating experiences I’ve had as an actor. But even if The Woman in Black didn’t scare me on set at the time, it will certainly be scaring people in the cinema.

I’m surprised that you were drawn to a horror movie.
Horror’s gone so far down the torture-porn road that there’s rarely anything interesting acting-wise or character-wise. But then you read a script like The Woman in Black and you go, ”Oh, yeah, that is what a truly creepy horror film can be.”

You and I once joked that one day they’ll probably remake all the Potter movies.
You know, if it’s the case that in 60 years’ time kids will just not watch any old films — and it’s a way to get those stories out there again, because they are fantastic — that’s a wonderful thing.

Sixty years from now, huh? Hopefully we’ll still be around to care.
I did put that a while in the future, didn’t I? If it happened before that, I’d probably be pretty upset. I think it’s weird to remake things that were pretty good the first time around. And I like to think we did a pretty good job.