Vampire Diaries’ Julie Plec on 100 Episodes: TV News : Vampire Diaries‘ Julie Plec on 100 Episodes, Crafty Katherine and Damon’s Downward Spiral [Warning: This story contains spoilers from Thursday s The Vampire Diaries. Read at your own risk!] “Of course it worked, I’m Katherine Pierce.” In true Vampire Diaries fashion, the milestone 100th episode ended with a huge twist.