Caroline will have some tension in the love department for season 4 of The Vampire Diaries. EP Julie Plec spoils that fans could see Caroline 'compromise herself for a relationship'.
"Klaus certainly is going to play a part in tormenting their relationship," Candice said. "I think that everyone has a dark side... Especially in young relationships, you do compromise yourself... I think there's definitely a possibility that we could see Caroline compromise herself for a relationship. If she's going to give him a chance, she's going to kind of have to forgive him for the Aunt Jenna [Sara Canning] thing, and all the terrible stuff," Michael said. "There's going to have to be some huge compromise. I mean, I think the compromise would have to be on his side, really. I'm not sure how willing she would be to move towards the dark side, though anything can happen. You never know."
You will see a major change in their friendship when the blond vamp doesn't like the way the new bloodsucker is acting. Hint: It may or may not have to do with a steamy moment Elena shares with the older Salvatore brother in episode four.