Weisz: 'New film hardest ever'

Mummy star Rachel Weisz and Harry Potter actor Robbie Coltrane have been talking about their new film The Brothers Bloom, about an actress who comes up against two swindlers.

They spoke to Newsbeat about being conned, mastering difficult card tricks and what we can expect next from Harry Potter.

Rachel, you had to learn a lot of skills for this, which was the hardest?

The hardest one for me was doing the card trick. Some people think that was a fake, it was someone else doing it. It was me. And it was a good five-minute card trick.

I didn't even know how to shuffle a pack of cards when I started this movie. I was taught by a magician from the Magic Circle in England and he came out to where we were filming and taught me for two weeks.

I had to do the card trick while delivering a monologue about my dysfunctional childhood. It was definitely the hardest thing I've ever had to do in my career.

What about driving the Lamborghini?

Robbie and Rachel with Brothers Bloom director Rian Johnson

I wasn't allowed to be in the Lamborghini when it was in motion. I was only allowed to be in it when it was still. They're what, a million pounds? What does a Lamborghini cost?

They didn't trust me behind the wheel. I'm actually a very good driver but they didn't believe me.

Have you ever fallen for a big cash con?

I don't think so. No-one's much tried. Robbie Coltrane was talking earlier about how it's kind of fun to be conned, it's like being seduced, that people come back to con men again and again and again. Sometimes the only reason they stop coming back is because they've run out of money.

It's seduction, isn't it, being conned? I hope this movie seduces the peeps.

Robbie, have you ever been conned?

Somebody tried to sell me a duff Rolex watch in a pub in Glasgow once. He said: 'This is a timeless classic Bob. It's got two dials for when you're abroad. If you're an international jetsetter, you've got the time in your home and the time in the country you're in'.

I turned it over and I said: 'It's got a stainless steel back. Rolex's don't have stainless steel backs'. And he said: 'Aye, it's a phoney. Sorry about that' and walked away!

Any fun stories from behind the scenes?

Rachel sports her Roland Mouret frock on the red carpet

Hundreds. The whole thing was fun. I can't think of a particular instance. Dan Aykroyd, who I worked with once, said, 'Just make things up'. So there was the day the monkey exploded. That was great.

It was just fun day to day. It was like being on tour with a band. I loved it.

So are you enjoying the downtime from Harry Potter?

I'm actually producing these days. I've got three things on the go. I'm trying to knock one of them out before we start filming Potter seven in February. There's going to be downtime between film one and two. You know, they're shooting it in two parts, so there'll be a week or two in the middle.

I'm an exec these days, so I'm going to have to start wearing a tie and being rude to people. Slamming the phone down and telling lies.

Each Harry Potter film seems to get bigger and bigger.

They were always written as another year in the children's lives and they're 17 now of course. So life has changed for them.

Romance is in the air. The threats get more and more threatening as his powers and knowledge and all of their powers and magic get stronger. They have to up the anti. The books are like that, that's the way they're written.

Rachel Weisz and Robbie Coltrane were talking to Newsbeat entertainment reporter Kev Geoghegan.