Samantha Cameron

Looking after a disabled child pushes you to the limits of what you can cope with... physically, emotionally. It's because there's this baby, this child that you love more than you can possibly imagine, in some way more than a normal child because you worry about them 24 hours a day. But at the same time you are so, so proud of them.

The truth is I am not a very hands-on political wife; I don't get involved in day-to-day Downing Street life. They don't need me interfering, but in the evening, we will talk about each other's day. I try to stay out of the Westminster village. There are times when I will be surprised and curious about what's been announced.

The historical novelist has to consider what has actually happened, while the SF writer is dealing in possibilities, but they are both in the business of imagining a world unlike our own and yet connected to it.