Screenwriter and author Anthony Horowitz is recovering after slipping a disc in his neck. The Stormbreaker scribe was forced to pull out of appearances at South Africa's Franschhoek Literary Festival earlier this month (May13) due to "medical reasons", and Horowitz has taken to his Twitter.com page to detail his injury. In a series of posts, he writes, "Huge apologies to everyone I let down in S. Africa. A slipped disc in my neck - horribly painful. I have now slept for 100 hours... It's been a rough few weeks."