I was interested in the ripples of feminism passing through Britain and Ireland in the mid-Seventies - how the reverberations of the feminist political movement were being felt in suburban households. So many novels end with a marriage.

When I worked at The Independent newspaper, I had colleagues who would laugh and say that whenever they picked up the phone to my dad and heard his accent, they thought they were about to hear a five-minute warning to get out the building. People in Britain have always thought it acceptable to make racist remarks about the Irish. The prejudice underlying that supposed joke was everywhere.

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.

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.

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

I have two sisters, and I think siblings are always going to be irresistible for novelists. They have been throughout time and they'll continue to be.

I don't want to be influenced as to what I write in the next book, to hear those voices in my head when I'm writing. The idea of second-guessing your reader is dangerous, trying to please some notional reader looking over your shoulder, instead of just yourself.