Have you said goodbye to the “Harry Potter” films?
JI: I came to the end of the line last Christmas. Sometime in December, I think it was. I’ve been trying to milk it as much as I can with a bit of ADR and publicity and stuff because I can’t bear to say goodbye. I don’t think any of us can.

What is it exactly that you can’t bear to leave — the people, the character, the story itself?
JI: All those and more. There’s lots to love about “Harry Potter.” All the things you normally experience on films, the very opposite is true of this. The set is a very happy and comforting place. Most sets are places with a throbbing undertone of fear that everyone’s taken the wrong job in the wrong thing. That no one’s going to watch the film, no one’s going to like the story, no one’s going to work again. Actors generally can float above that stuff, but there’s something very different going on with “Harry Potter.”

You know you’re making a story that you love taking part in and that you know people will obsess over. It’s the difference between throwing a party and wondering if anyone’s going to come and having the party people are having to wait to get into. Everything about it always feels right. So that’s just on the storytelling front. And then on the sheer star-struck front, I still pinch myself after almost a decade of it, that I get to go to work with the kinds of people I do.

Where on most big special-effects films, you complain about all the time sitting around, there was never enough time sitting around if you’re sitting around with Maggie Smith and Alan Rickman and Bill Nighy and Jim Broadbent and Imelda Staunton and on and on.

Did the book series coming to an end – and knowing that ending – change your interpretation of the character filming movies based on earlier books in the series?
JI: Yeah, I feel quite lucky actually because Lucius had an actual journey. There’s a number of characters that didn’t change that much but he started off being such an arrogant [jerk] and a monstrous bigot and racist that I was hoping he’d get his comeuppance at some stage. But I didn’t imagine I’d be so publicly deflated and humiliated.

Lucius thought he’d stand by Voldemort’s side and fall with him. Instead I’ve been completely emasculated by him and rejected by everybody, and as an actor it’s a tremendously juicy thing to do, not play the same part time after time. So after all that early hope and arrogance, I think it is very satisfying to the audience and to me to see him so crushed.

Did you have any real-world model for your interpretation of Malfoy?
JI: When I got cast and looked at the first film, I saw Alan Rickman, who is the world’s greatest bad man and was tremendous as the sinister Snape, and I thought, “What the hell am I going to do? How am I going to pull off anything that’s in any way distinctive?” All I had to do was look around.

I don’t know what you have in America, I’m not familiar with your rabidly right-wing politicians, but we have plenty of people in Europe standing up and saying the kinds of things and thinking the kinds of things Lucious thinks about racial separatism and racial purity and it’s really not far-fetched at all. It seems ripped from the daily headlines. So that sense of arrogance and entitlement is something you’ll see in any newspaper in Europe on any given day.

Would you say Lucius is the worst villain you’ve played?
JI: No, he’s not the worst. He’s a terrible coward. And in the end he doesn’t really get to do very much. He’s all bark and no bite, really. If he were capable of doing anything, he might be among the most vicious and the consequences would be calamitous.

But he’s far more concerned with what he looks like and what he sounds like in the mirror and being in the newspaper than he is about taking action. And I think Voldemort’s quite right in seeing that he’s addicted to his status and addicted to his swanning around and spending too much time at the tailors and not enough time getting his wand sharpened.

I read how you read the first four “Harry Potter” books in three days’ time. Are you a big fan of children’s or fantasy literature?
JI: No, not at all. In fact I was slightly sniffy about these books. I didn’t understand why some of my contemporaries were laughing at them and asking if I’d read them. I take the tube a lot in England and grown-ups – people of drinking and volunteering for the army and marriageable age – were reading children’s books.

I got slightly stuffy about it until I dove in myself. They’re so beautifully written, you’re transported. There’s great value in that. They’re such a beautifully realized escape. It’s like sitting on a magic carpet when you open the front cover.

There’s so much great detail in the books.
JI: I didn’t have kids when I got the job in “Chamber of Secrets.” They’ve been very generous with our schedule to allow me and lots of actors to do other things. But one of the things they did was schedule around the birth of my first daughter on “Chamber of Secrets.” So subsequently I’ve read an awful lot of children’s books. Not only did I enjoy the “Potter” books at the time, in retrospect, I see just how successful they are at appealing to many different ages. And they mean different things to kids at different ages.

I’m actually on the first round of reading it to my 5-year-old now and I’m wondering at what point I stop. She keeps wanting to go on to the next book and I’m thinking about what point they get too grown-up. But she’s absolutely got her mental hooks into it and won’t let go. She’s seen the first two movies. I think they get too scary after that for her at this age.