Yes, I have read them. They both feature characters from 'Shadow of the Wind' but are not really sequels or prequels in the traditional sense. I enjoyed them both but my favorite is still 'Shadow'--oh, if only I could spend a day in the Cemetery of Forgotten Books! Zafon started out writing novels for young adults. I've read one, 'The Prince of Mist;' well written and kinda spooky. It reminded me of the Weeping Angel stories on Doctor Who.