I still have a stammer. I hate it; I loathe and despise it. But it's always there, and I have lots of ways to conceal it. I can conceal it now but I'm not good on the telephone. I get my husband to make dentist appointments. And I hate live radio. Hate it. I really try to avoid it at all costs. But it's always there. Stammerers become skilled at sentence construction and synonyms: we have to be. Faced with a problem word, we need to have instant access to eight others we could use instead - ones we could say without stumbling. I think my stammer is a huge part of my being a writer.

I try not to be too precious about my writing, and I try to be willing to walk away from it for a few hours when something's not working, to let things percolate a bit. I try not to hide myself away from life too much, because I think that's a risky thing for a writer to do.

I always had the urge to write. Not in the sense of wanting to be a writer, but just writing things down, getting words on a page. Graphomania, it's called. I've always had a definite love of stationary products - I used to spend all my pocket-money on pens and notepads. I still do, in a way.

We're much better at dealing with dyslexia today than in 50th, but reading difficulties are still a problem in the U.K. I believe there's currently something like eleven thousand functionally illiterate adults in the U.K.

Why isn't life better designed so it warns you when terrible things are about to happen?

We all have a family, whether we like it or not; we all come from somewhere, and there's something strange in the way you have, with siblings, two or three personalities yoked together for life. You grow up thinking those family relationships are set in stone and then you get older and realize they're not. They're always shifting.

I think all families have these secrets, and it's sometimes the strangest things that bring them out. That was part of my interest in the heatwave, in heat as a catalyst for uncovering truths. I was reading Alice in Wonderland to one of my kids recently, and I remembered that it starts on a really hot day. Alice falls asleep because of the heat; the whole story is predicated on falling into a heat-fueled dream.