"If you could make a story about Caroline being the "invisible" doppelganger, where she was once in-love with Kol." –Artemis Prim
So this follows the doppleganger mythology of season three because anything more than that gives me a headache.
He meets her on Beltane, a night sacred to the witches. Originally descended from the Fae, they feel closest to nature the most that night. Even his father knows better than to meddle with this special night. The wolves themselves keep far away when the witches have their little rituals, dances and animal sacrifices to honor the spirits.
It's on one of these nights he finally takes notice of the pretty blonde witch dancing with the other witches her age. She's all sunshine and bright starlight as she laughs and he's entranced. He finds himself going to her, drawn by some unseen pull and he stops in front of her as she stares up at him with wide blue ocean eyes. He offers his hand for a dance and she takes it eagerly, stepping into rhythm with him like she's done so many times.
Her body molds against his, all curves and softness and he wants her more than anything before in his life. The ancient thrumming underneath their veins between flesh and bone push them to dance until he feels flames almost lick his skin. He stares into her deep ocean eyes and wants to make her his. She understands with the age old secrets of women and life.
She takes his hand and leads him away from the crowd, away from the noise and revelry and deep into the woods. She sheds her clothing and divulges his, laying down on the soft earth and offering herself to him. He takes and gives with worshipful care and he can hear the songs of time and heat shared between them. He chose her and she chose him.
She leaves him at dawn to return to her home. She kisses him goodbye or good morning with the all sweetness in her before promising to see him again at dusk. He anticipates her touch through the day, remembering how she feels underneath him, how she tastes in his mouth. But when night comes, he has one last dinner with his family before his father plunges his sword into his chest cavity and to his heart.
He should've known, should've understood that the blood laced in his wine was not only of the girl his brothers loved but also the girl he loved as well. Carolina's blood was a rich, bitter taste that memorized itself on his taste buds until all he wants to do is destroy and feed. And he does so for many years until he can't look at himself in the mirror without remembering her, only her. The girl he chose on Beltane and lost the next night.
He awakens in a box that he has long outgrown. He hates every inch of the dark wood coffin, wants to set it on fire and let the flames feast on every second he wasted inside of it. He wants to set Niklaus on fire too but the indestructible bastard enjoys being in the world and he makes it hard for him to be killed. He wishes maybe for his father to be there for one bitter second because nobody has ever hurt his brother like Mikael before pushing the terrible thought away.
Instead he attends a frivolous ball the next night, looking his best to try and convince this miniscule town they were more harmless than satanic. People were attracted to pretty things after all and would lie to themselves to justify for whatever tickled their fancies. She's fulminous when he first sees her. Lightning coursing through him when she enters the ballroom dressed in twilight blue.
It's not Beltane and she's not the same but he'd know her even more in the dark. She smiles at those around her and he's drawn to her by a familiar unseen pull. He takes her hand and says, "Hello, beautiful."
She laughs and asks him who he is. He tells her his name like it was a secret between them. "Kol Mikaelson," He takes in her lovely face and never wants to look away. "What's yours?"
"Caroline Forbes," She does an awkward, endearing little curtsy. He asks for a dance and she accepts. He twirls her around the dance floor and she moves with him like she's done so forever.
He has practically no knowledge of this century's rules on courting but Caroline guides him through it with a sweet laugh and jokes that go over his head. She calls him a 'grandpa' and in return he calls her an 'infant'. Sometimes at night he can feel his millennium old bones creaking underneath his aged muscles and skin but when he sees her in the morning it all fades away. He becomes renewed like a waxed moon under the glory of her ocean-deep gaze.
She takes him to amusement parks and to watch films about space and sparkling vampires. He makes her watch old films and dance to jazz music. She makes him feel alive. He wants her with him forever.
She knows about what he is as most of her friends are or are on their way to becoming vampires. She is still human miraculously despite the death tolls around the town and he offers immortality to her like a ring. She contemplates it for days that turn into weeks before she tells him her answer in between sheets and her soft breath on his skin. "I want to be with you forever."
He is more careful with her than he ever has with anything in his life, like she is porcelain and he's a clumsy boy that will break her. She gasps as his teeth pierce the fragile vein on her neck and he tastes the same bitter taste memorized in his taste buds before he pulls back, gasping, unseen flames licking his skin. He convulses on the floor of Caroline's bedroom, her hovering and screaming at him as the world spins into darkness.
He awakens at dawn, Caroline looking relieved to see him conscious again. Her soft fingers caress his face as he blinks up at her. Her ocean-deep eyes are tear-stained and he tugs on her hair lightly till she laughs from release. He feels warmer than he has in a very long time and he takes her hand and places it over his beating human heart.
"Failsafe," He tells her. His clever mother made this girl before him as a failsafe in case the spell had gone wrong. He wants to laugh and so he does.