We all know the story of the original family , the Mikaelsons . Mikeal , Esther , Elijah , Niklaus , Finn, Kol , Rebekah and Henrick . But you're forgetting one . One very important member of the Mikaalson family . Alexandra Mikaelson . Elijah's twin sister . You see , shortly after the Mikaelsons became the first undead family , Alexandra Nikolina Mikaelson vanished . After a few centuries , she became nothing more then a ledgend . A fairytale . But what will happen when she comes back ?