It involves a drunk Caroline, friendly Kol and Klaus on episode fifteen, where Damon makes Caroline distract Klaus so they can dagger Kol. But instead she actually accepts Klaus' offer which leads up to her being drunk which opens up her mind and she accidentally projects all the memories of what Damon did to her into Kol and Klaus' heads. Kol is the one that has a crush on her instead of Klaus but Klaus sees her as a sister. Just a lot of Scooby Gang bashing - And possibly their deaths. Thank you @Tribridbeauty for this amazing idea