Recently, it was revealed that Carolina was MIA because she was on a mission to save her daughters from having to “merge” (a nice way of saying the stronger twin will absorb the power of the weaker twin) on their 22nd birthday. This ritual was first explained on TVD, when the twins’ biological mother, Jo — who had a twin named Malachai “Kai” Parker — hid her powers, forcing Kai to be trapped in a prison world.
However, Kai ultimately escaped and killed Jo, which is why Caroline carried Lizzie and Josie in her womb following her death. Now, she is determined to prevent that from happening to the girls nearly two decades later.
“Alaric knows [Caroline is] actually off doing other things that have to do with the long-term survival of their daughters,” Julie added. “So the mystery of, where is Caroline, why isn’t she coming home for their birthday, that kind of thing is gonna be part of our story in the hopes that one day we’ll be able to have her walk through the doors as well.”
On second thought, it might be a good idea to watch The Vampire Diaries and The Originals ahead of Legacies.