Watch The Vampire Diaries season 4 episode 15 online. WHen Stefan returns in Mystic Falls with Jeremy and Elena , Caroline is immediately worried about the state of mind of Elena. Stefan reaches to Dr. Fell and Matt to help them. Meanwhile, Damon relays somber news to Rebekah in the island and is surprised at her reaction. Together, Damon and Rebekah learn an unexpected bit of recent history from Vaughn (guest star Charlie Bewley). Everyone is horrified when Bonnie (Kat Graham) reveals the rest of Shaneâ€™s (guest star David Alpay) plan. Finally, after Damon does his best to help her, Elena comes up with a plan of her own.