Months following their violent and deadly showdown with the powerful witch Dahlia, a rift continues to divide brothers Klaus and Elijah, while Freya searches for a way to heal their fractured bond and return their family to the way they once were. Meanwhile, Klaus' suspicion piques when he learns that an old vampire friend named Lucien has arrived to New Orleans with a mysterious agenda involving the Mikaelson's remaining sire lines. Elsewhere, Elijah questions whether he can truly forgive his brother for his mounting offenses, while Hayley struggles with being cursed to her wolf form in the bayou. In the French Quarter, Vincent and Cami assist Detective Kinney after a series of gruesome discoveries are made, leading them to believe they may have a serial killer on the loose. Finally, Marcel, who has regained control of the French Quarter once again, tries a new strategy to recruit vampires, while Davina, who is now Regent to the New Orleans witches, makes a decision that will find her and Marcel on opposite sides of an escalating conflict.

After discovering that poachers have begun taking out werewolves in the bayou, Elijah and Jackson grow concerned for Hayley's safety when she fails to show up during the full moon. Meanwhile, Davina, the only one with the answer to Hayley's whereabouts, plots ways to use that to her advantage. Elsewhere, Cami approaches Klaus with her theory on who is behind the series of murders in the French Quarter, while Lucien delivers to Elijah an unsettling warning about the war brewing among the sire lines. Finally, after receiving a dire prophecy about the future of the Mikaelson siblings, Klaus takes extreme measures to determine the validity of this potential impending threat.

With tension running as high as ever, Klaus and Elijah are forced to come together in order to uncover Lucien’s true motives in New Orleans. Cami is caught off guard when she finds herself face to face with Lucien and is surprised when he reveals some unexpected information about his past with Klaus. Elsewhere, a mysterious figure presents an enticing offer to Marcel, while Hayley turns to an unconventional way of coping with her current situation. Finally, an old acquaintance from Elijah’s past arrives in New Orleans and delivers some startling news involving the growing threat to the Mikaelson siblings.

As the war among the sire lines continues to grow, Klaus receives an unexpected visit by a figure from his past. When Elijah suspects that Tristan is hiding something, he enlists Marcel's help to find out what he's up to. Elsewhere, Davina struggles with her role as Regent and seeks advice from Hayley. Finally, an ancient secret that is uncovered threatens to tear the Mikaelson brothers apart for good.

When Elijah and Freya realize that Rebekah may be the target of The Strix's latest plan, they do whatever it takes to protect her. Elsewhere, Klaus spends time with Aurora to figure out where her loyalties lie, while a dangerous run-in with a member of The Strix leads Hayley and Marcel to make an unsettling discovery. Finally, an elaborate scheme created by Lucien leaves Cami faced with a difficult decision to make and Detective Kinney fighting for his life.

When a dangerous affliction threatens to expose one of her siblings, Freya searches for a way to reverse the crippling curse even as she finds herself the target of The Strix's latest plan. Elsewhere, Klaus keeps a watchful eye over Cami while she attempts to help Detective Kinney, whose life has begun to spiral out of control as a result of Lucien's compulsion. Meanwhile, a confrontation with Marcel causes Vincent to reevaluate his decision to stay out of witch business, and Hayley's attempt at a quiet Christmas with Jackson and Hope results in an unexpected surprise.

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.