"I've published over 100 books - and that is divided about 50/50 adult and young adult. Lately, I have been writing more YA, which is such a great genre to write it. I don't have a favourite (I usually say it's the last book I've written), but certain books do stick in the mind. My very first YA novel, The Children of Lir, will always be special to me, and, of course The Alchemyst because it was a series I'd wanted to write for ages."