|“||If you're in the market for a gentlemen, Mary-Alice Claire, I'm afraid you have the wrong Mikaelson brother.||”|
Kol and Mary-Alice had an alliance and history at the turn of the 20th century, before he was once again daggered by Klaus. After years of torment at Klaus's whims, Kol made plans to take down his brother and his witches in 1914, allying himself with Mary-Alice and Astrid to help him by creating dark objects for him to use, and to spell the one of the daggers to work on his brother. Kol and Mary-Alice had a romantic relationship in addition to their alliance, which is assumed to have continued until their alliance eventually fell apart before Kol was daggered.
Kol was undaggered again in 1901, and lived in New Orleans with his siblings. It was in 1914 that he started building alliances with the witches of the French Quarter and allied with Mary-Alice to work to take down Klaus and his witches. Despite this alliance and apparent romantic relationship, Mary-Alice expressed concern for Kol's real intentions, noting that she knew the stories about how he would use witches and then discard them when he was done with them. Kol insisted that these were lies his family had created against him, telling her that Klaus would make New Orleans vampire country, and an alliance with him would help her ensure the safety of future generations of her family.
Kol began to teach Mary-Alice and a witch named Astrid a magic that he had learned in Arabia, called Kemiya. It centered on the boundaries between magic and science, and would allow the make up of an object to be changed. The three of them created numerous dark objects to be used as weapons in the war to be waged against Klaus. He intended on building up the skills of the witches so that he could have Mary Alice and Astrid spell a dagger so that it would work on Klaus and he could put his brother down the same way that he'd had decades stolen from him. One of the tombs in the Lafayette Cemetery served as Kol's clubhouse and where he, Mary-Alice and Astrid did their spells and stored their weapons.
When Mary-Alice and Astrid remained unsuccessful at turning the silver dagger into a golden one, Kol grew frustrated with them for their failed efforts. When Mary-Alice explained that they needed a bigger diamond to draw energy from, she told him of a woman who possessed one. When Astrid and her explained that she only left her home to attend church, they knew Kol would kill her to gain entry to her home and to the diamond. What Mary-Alice didn't expect, however, was the Kol would also kill half the church parish for fun while he killed her. Astrid was furious with Kol for his malicious behavior, claiming that her and Mary-Alice would no longer help him. Mary-Alice disagreed, though, saying that they had gone too far to turn back. Kol, with blood of his numerous victims on his face, seemed pleased by Mary-Alice's loyalty and passionately kissed her before departing, leaving Mary-Alice with the blood of his victims on her lips.
Kol, Mary-Alice, and Astrid broke into the mansion that held the diamond. Kol found it and told them to meet him at the cemetery. Kol left while Mary-Alice revealed that she planned on betraying Kol, sealing off the "playhouse" so only a Claire could open it and he couldn't get back to his dagger. However, outside he was confronted by Klaus who forced him to hand over the diamond and then had his own witch trap Mary-Alice and Astrid inside the mansion with a boundary spell.
She payed dearly for her allegiance, trapped in the mansion forever, and Kol was daggered as a result of his tirade against his brother.
Throughout The Originals Series
In Chasing the Devil’s Tail, Kol told Davina about his alliance with Mary-Alice briefly when asking her to use her blood to unlock the tomb he'd frequented in 1914. He said that he pissed off the prettiest of his witches, referring to Mary-Alice, and that was why she locked him out.
In The Map of Moments, It's shown that Klaus waited for Kol to come out of Dowager Fauline Cottage to wait for his witch to curse the cottage as punishment to Mary Alice for allying with his younger brother.
Mary-Alice : "Just once, Kol Mikaelson, you might greet me like a gentleman?"
Kol : "If you are in the market for a gentleman, Mary-Alice Claire, I'm afraid you have the wrong Mikaelson brother. Where is Astrid? I need two witches before the lessons can begin."
Mary-Alice : "She thinks you can't be trusted. We've all heard the stories of how you use the witches and then discard them."
Kol : "Lies. Propagated by my wicked family, love. I hold witches in high regard. You know, if Klaus says his way, you'll all be dead. This will be a vampire country, don't you want to keep you all in safe, for all the future generations of Claires to come?"
Mary-Alice : "Why are you so keen to help us? What do you get out of this?"
Kol : "As soon as we get rid of Klaus's witches, we are going to get rid of Klaus. Follow me, Mary Alice. We are going to change everything."
Kol : "It's the intersection between science and spirit, darlings. With the right chemistry you could realize your wildest dreams."
Kol : "A blade that can make a thousand cuts with just one throw. Those traitors who dare work with my tyrannical wanker of a brother, wouldn't have a chance to say a word of their pathetic spells."
Kol : "You've been working on this for weeks and my family goes even more insufferable during the holidays. We need to finish."
Mary-Alice : "We've tried everything, Kol. We need a bigger diamond."
Kol : "There is no bigger diamond."
Mary-Alice : "There may be. That gossip Genevieve had a rumor that the dowager Folly keeps a massive gem hidden inside her mansion. That's why she never leaves. She's worried someone will steal it."
Kol : "She never leaves, you say."
- Kol considers Mary-Alice as the prettiest witch in the group which he worked with to take Klaus down in 1914.
- Mary-Alice was Kol's favourite witch in 1914, and they had an apparent romantic relationship, though it seemed Mary-Alice's feelings for Kol were more genuine than his for her.
- In the present day, Kol aligned himself with Davina, teaching her the same magic he taught Mary-Alice to continue his plan from 1914 - to create a dagger that would put down Klaus, and only him.
- While his relationships with Mary-Alice may have more been for fun than actual feelings, Kol's feelings towards her descendant Davina are very real, who he also flirts with in addition to working on magic with her.
- The two of them, along with Astrid, created many dark objects that were seen in Season One.
- Like many of the vampires in this universe, Kol was involved with an ancestor of his late ex-girlfriend, Davina Claire. Mary-Alice was that ancestor in Davina's family line that Kol was romantically involved with.