According to Zap2it, female vampires Lexi (Arielle Kebbel) and Anna (Malese Jow), who died in the show's first season, are among those who could reappear via flashbacks.
Speaking at New York Comic Con, Williamson also reportedly discussed a possible return to Mystic Falls for John Gilbert.
"I love David Anders, and I look forward to the moment that he does come back to our show," he said. "I can't say where or when or how that's going to happen, but he's Elena's father. There's too much potential there."
> Accola: 'No Diaries characters are safe'