S4, E18: Elena and Rebekah (recurring guest star Claire Holt) take off in search of Katherine and find themselves in a small town in Pennsylvania, where Elena has a surprising encounter with another old acquaintance: Elijah (recurring guest star Daniel Gillies). Stefan and Damon are both concerned about Elena’s state of mind and are determined to do what’s best for her, but she makes it clear that helping her will be difficult. Damon is not sure how to react when Stefan reveals his unexpected plan for the future. Meanwhile, in Mystic Falls, Klaus receives Caroline’s reluctant help and comes to a new understanding of Silas’ powers.