"Caroline and Bonnie were gone to help Abby with her transition — it's taking a toll on Abby," Accola explains to TVGuide.com. "We're going to learn about what happens when a witch transitions and how that differs emotionally. I love that Caroline's taken a note from Stefan last season and has become a mentor for others throughout their transition."
In addition to helping out Abby, Caroline will continue to lay the groundwork for Klaus to free Tyler of his sire bond.
"Caroline and Tyler will be reunited," Accola promises. "Caroline is playing into Klaus' games so much at this point because she has her own game going. She's saying, 'Well if you really care, let him go, release him.' She's been doing her own work to release the bond back in Mystic Falls so we're going to see if that pays off."
Watch this week's Vampire Diaries Bite for more on the Tyler-Caroline-Klaus triangle: