Betrayal at the masquerade ball? Klaus and Rebekah come together to attempt to unravel Marcel's empire from within, in spite of Elijah's concerns. They enlist help from Sophie.

Klaus tries to get adapted to his new duties as he became the king of the city. He offers Marcel a compromise and he fixes his relationship with his siblings. Davina feels betrayed by Marcel. She finally finds an ally, Cami.

In 1919, Rebekah worked in a sanatorium. She finds herself back there and locked up as a witch who is seeking revenge plans to reveal her darkest secrets. Elijah makes a decision that puts the others in further danger.

Kieran lashes out unexpectedly after Cami's good intentions don't get her what she expected. Elijah and Klaus can't agree on how to handle the Crescent Wolves. Elijah visits the bayou were he is witness to a explosion that see's hatred between the communities intensify. Hayley learns about her family from Marcel.

Davina takes Mikael to a cabin to heal from his wolf bites. Klaus searches for them. Elijah, Marcel and Hayley try to rescue some young wolves.

Finn puts a spell on the compound, trapping wolves and vampires. Klaus takes Cami to the safe house, then confronts Kol about Rebekah's whereabouts.

While searching for a way to vanquish Dahlia, Klaus is faced with another threat.

In order to uncover what his old acquaintance Tristan is really up to in New Orleans, Elijah considers attending a gala thrown by a mysterious group of ancient vampires known as The Strix, while Hayley invites herself to attend with him. There, Marcel is approached with an enticing offer made by a mysterious woman named Aya, but he quickly realizes that things are not always what they seem. Elsewhere, when a vital component of Lucien's plan goes missing, he and Klaus form a tentative alliance in order to find it.

While Klaus finds himself dealing with pressing matters at home, Elijah reluctantly aligns with Aya after learning that she may have knowledge of an elusive weapon that could kill an Original vampire for good. Meanwhile, alone and shunned by her coven of witches, a desperate Davina is left conflicted after she is approached with an enticing offer that could bring her one step closer to reuniting with Kol.

Dangerous foes descend upon New Orleans in an attempt to take down Klaus once and for all when rumors spread about the remaining white oak bullet. As the threats grow, Elijah urges his siblings to lay low at the compound while Marcel, Vincent and Josh chase down a lead involving a mysterious vampire named Sofya. Meanwhile, Kol is forced to face his brother Finn, the person responsible for his death; and Klaus and Hayley seek shelter with her former pack and stumble upon some unsettling news.

After receiving new visions of the looming prophecy, Freya uncovers that her family is on a collision course with a dangerous new enemy. Meanwhile, with the help of Detective Kinney, Vincent and Kol travel to the ancestral world to put a stop to the witches and take back their city once and for all. Elsewhere, Klaus and Elijah confront Marcel after a heartbreaking plan gone wrong has sent him spiraling.