So I guess you’re fabulously rich beyond your wildest dreams, right? When I sold the film option to How I Live Now, I had a figure in my head that, I'm embarrassed to say, was huge. And wrong. Writers are generally paid a small amount for the film option, and then a very small percentage of the shooting budget. If your film has a massive budget (ie, lots of special effects, huge stars, worldwide locations), and if there are seven of them (cf, JK Rowling) this can make you rich. If the film has a smallish budget with mostly unknown actors, that percentage is not a license to buy luxury cars. I'm thinking of getting a new computer, though this one is, strictly speaking, not broken. (Oh, Meg, you crazy kid.)

Do you have a say in the casting? The decisions made by my lovely producers over the past few years have made me trust them implicitly, so I have no reason to think they'll cast Meryl Streep in the role of Daisy.

What if they change your novel? I've read the screenplay, and think it's actually better than the book. As a writer, you can get away with all sorts of omissions and fudges that don't work on film. When I first talked about the book with the producers, they asked questions along the lines of -- So, um, who is the enemy in How I Live Now? And how does Daisy end up leaving England? Do they leave Piper all alone? I'm afraid my answer to all three was, Duh....

Has Johnny Depp been in touch? Do you mean has he invited me to brunch? Sadly, no. (see gratuitous picture above)

Can you veto the decisions made by your producer/director? Given that I trust them,I don't question their decisions, though they're always great about keeping me informed and asking what I think. I suppose it would be possible to take the war out of How I Live Now, re-set it in Orange County, and rewrite it as a porno film, but this doesn't feel like one of those situations.

When will the film be released? There's talk of starting to shoot at about this time next year, and as a rough average, I'd guess nine months from start to release -- so maybe, late 2011?

Why don’t you look more excited? (My daughter always asks this one.) Well I am, actually, madly excited. But I’m also incredibly suspicious of good luck (I keep thinking of the guy who won the lottery, fulfilled his lifelong dream by buying a Lamborghini with the money, and then crashed it into a mountain on the first day and died. Dark, moi?) Also, I remember Deborah Moggach’s story about the filming of her book, Tulip Fever – as I recall, they were all standing around in costume, on set, waiting for someone to shout "action!", when Gordon Brown (as Chancellor) did something with the tax laws that affected the film industry, and they pulled the whole production. What stuck in my mind from that story was Deborah saying she had to get rid of 10,000 tulip bulbs in a weekend. I was a more conscientious gardener in those days, and nearly wept that I hadn't known her.

Will I still be able to talk to you now you’re famous? I'm not talking to anyone till I finish the damned book.