Vampire Novelist's Reputation at Stake

Stephanie Meyer had managed to write the extremely popular Twilight series and developed a legion of fans. Now that is coming back to bite her a little lower than the neck. The last book was apparently so poorly written that Entertainment Weekly gave it a D rating and many fans of the series are now talking about setting fire to it. That makes me wonder two things. First, could there have been some extremely heavy editing or even ghosting (thematically appropriate, at least) on the earlier books? Not that it's impossible for an author to have an off volume, but when it goes that far south, you have to ask.

Secondly, fame is clearly a double-edged sword. Who's going to buy the next book?