It's somewhat disquieting that the same parents and educators who are horrified by the notion of child soldiers have bestowed upon 'The Hunger Games' a double mantle of critical praise and global bestsellerdom.

We used to flock to watch gladiators, public torture and executions. In more recent times, our appetite for mortal violence has been sublimated in sports, photorealistic video games, film and literature.

One of the reasons I wrote 'Airborn' was that I'd fallen in love with the great passenger airships which flew in the '20s and '30s. Their time was short-lived. They were frail, they tended to crash; and they could never be as fast, safe and efficient as the airplanes that replaced them.

The more I worked on 'Half Brother,' the more it seemed to me the story was really about love in all its possible forms - how and why we decide to bestow it, or withdraw it; how we decide what is more worthy of being loved, and what is less. We are masters of conditional love.