" you may not want to visit Series Eight, a bleak and stony world, or Series Six, where the worlds are covered in ice. And don’t be fooled by Series Eleven, as it’s not a Series at all, but just one world. But you may like Series Five, with its islands and mermaids. And if you’re looking for a good cup of hot chocolate, Series Nine is the place for you. "
― Diana Wynne Jones , Charmed Life (Chrestomanci, #1)