All the time I was plowing through books on dyslexia, I found myself asking: what if, what if? What if you were a kid the 1950s with this condition, when there were no books on it, when there was no understanding of it. I remember kids in my class at school who just didn't seem to progress in their reading. There was no extra help. People just thought, "Oh, he or she isn't so bright, or they're obstinate."

It is a terrible thing to want something you cannot have. It takes you over. I couldn't think straight because of it. There was no one else, I realized, whom I could possibly tell.

All the time I was plowing through books on dyslexia, I found myself asking: what if, what if? What if you were a kid the 1950s with this condition, when there were no books on it, when there was no understanding of it. I remember kids in my class at school who just didn't seem to progress in their reading. There was no extra help. People just thought, "Oh, he or she isn't so bright, or they're obstinate."

While I was writing the book, one of my children was diagnosed with dyslexia. Dyslexia is a very tiny word for a wide-ranging neurological condition that affects different people in different ways. But I was reading an awful lot about it, to try and find ways of helping my child. I think a lot of fiction comes from this desire to confront unanswerable questions, and it's heartbreaking to see your child, a bright child, struggling so much with something that others are finding so easy. It's such an assault to the child's self-esteem and, as a mother, it's hard to watch.

We always planned to move back to the Republic but it never happened, I'm not sure why. My dad is one of those immigrants who never leaves the place he came from. He talks about Ireland all the time. If any Irishman wins at any sort of sport, he sees it as a personal achievement.

As you'll know yourself, there are these moments when you're writing a book when one remark or moment will pull everything together and you'll think, "That's it. I've got what I need."

I met a retired police detective. And he said to me that the interesting thing about heatwaves, from a police perspective, is that the number of people who just walk out of their lives when the weather gets unbearable is astronomic. He said the police prepare themselves for it - for a huge rise in the instances of missing persons. People choose to disappear when it's hot. It was fascinating.