Nadia is trying to save her dying mother, Katherine, and comes up with a frightening plan. Elena and Stefan are forced to help Nadia to proceed her plan after Nadia threw Matt in the safe, which Stefan spent the summer locked in. Bonnie, Caroline and Jeremy search for Matt's location, but the returning Rebekah saves him. Katherine, who continues to fight for her life, memorizes her time in Bulgaria back in 1492. Klaus also returns and confronts Caroline, which ends up with a bang. After Nadia leads them, Elena and Stefan are trapped in a house full of travellers who is doing an unknown ritual. However, Elena and Stefan are able to escape, and later Elena goes to Katherine to forgive her for all bad things that she did to her. Tyler returns as well and he catches up with the group. Upon her speech, Katherine attacks Elena and finish the ritual, officially becoming a traveller in Elena's body.