S4, E12: When Rebekah (recurring guest star Claire Holt) turns down Klaus’ plea to stop Kol (recurring guest star Nathaniel Buzolic) and protect Jeremy, Klaus turns to Stefan for help. After an angry confrontation with her father, Mayor Hopkins (recurring guest star Rick Worthy), over his unconventional approach to ending the violence in Mystic Falls, Bonnie has a frightening run-in with Kol, followed by an unexpected visitor. Klaus complicates the already tense feelings between Stefan and Damon by revealing a bit of Stefan’s personal life, then surprises Damon by asking for personal advice. Elena tells Stefan about her dangerous plan for Jeremy, leaving Stefan in a difficult spot. When the 1980s Decade Dance at the high school is cancelled by Mayor Hopkins, Stefan finds a charming way to make it up to a disappointed Rebekah.