You need only pop your head into a bookshop to see that young adult - or YA - fiction is one of the most popular commercial genres in the world. There is a good reason for this: people aged 12 to 18 tend to want fiction that captures much of the imagination and escapism of children’s books, but with more grit, more reality. They want to see the sticky or difficult parts of their lives reflected back at them. They want to feel seen.