Klaus Mikaelson, the original vampire-werewolf hybrid, has returned to the supernatural melting pot that is the French Quarter of New Orleans - the city his family helped build 300 years ago. Determined to help his brother, Elijah leaves their sister Rebekah behind and follows Klaus. Elijah learns that the beautiful and rebellious werewolf Hayley - Klaus' onetime flame - has fallen into the hands of a powerful witch named Sophie Deveraux. When Sophie reveals some life-changing news, Elijah realizes that the Original family may have been given a second chance at humanity and redemption. Klaus, however, is more intrigued by his recent unexpected reunion with his former protégé, Marcel, a charismatic but diabolical vampire who now has total control over the supernatural inhabitants of New Orleans. Klaus vows to reclaim what was once his - the power, the city and his family.

A FLASHBACK TO THE 1800s - When Rebekah arrives in New Orleans at her brother Elijah's insistence, she meets Hayley, who gives her some unexpected news. Concerned that her brother Klaus is up to no good, Rebekah seeks help from a reluctant Sophie At her wits' end, Hayley takes matters into her own hands, but things quickly take a dangerous turn. Determined to uncover Marcel's secret weapon, Klaus stays one step ahead and executes his plan. Meanwhile, after a run-in with Marcel, Rebekah is reminded of all the anger and disappointment Klaus has caused her throughout the years. Finally, Marcel enlists Davina's help in his own dangerous plan.

After discovering interesting news about someone in Marcel's inner circle, 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, who is reluctant to get involved for fear of the wrath of Marcel's secret weapon, Davina. Rebekah sneakily invites an oblivious Cami to a huge vampire party thrown by Marcel, managing to anger Marcel in the process. Elsewhere, Hayley learns from the witch Sabine that the supernatural creatures of New Orleans are reacting to the potential existence of a hybrid baby.

With the annual Dauphine Street music festival around the corner, Davina, itching for a night out, convinces Marcel to let her attend. Marcel cautiously obliges but asks Cami to keep a watchful eye on Davina. Agnes convinces Hayley to visit a mysterious doctor in the bayou where she makes a shocking discovery. Meanwhile, Klaus takes a special interest in Cami, who reveals some alarming information about her past, and a determined Rebekah is on a mission to get to the bottom of a recent strange encounter involving Elijah.

Angered by recent events involving the safety of his unborn baby, Klaus demands answers from Sophie, believing she was involved. Sophie reveals to Klaus and Rebekah a troubling secret from her past. Meanwhile, Marcel asks Klaus to accompany him to the bayou after gruesome remains are discovered, while Rebekah, Sophie and Hayley set off on a mission of their own. Davina confides in an unexpected ally and reveals shocking information about the witches, ultimately leading to a disturbing revelation.

When Klaus discovers Hayley's life is being threatened, he goes to extreme lengths to protect her and their unborn baby. Having a difficult time dealing with the tragic events of her past, Cami turns to Father Kieran for guidance. Feeling as though he can trust no one, Marcel visits an old friend to seek out some advice, while Davina takes steps to learn how to control her magic. Finally, Klaus delivers some surprising news to Father Kieran.

When someone from Hayley's past makes a startling revelation, she grows concerned for herself and the baby. Amidst growing tensions between them, Klaus and Elijah turn to Sabine for help in locating Hayley, who has gone missing. After making a trip down to the bayou, Klaus has a surprising and dangerous encounter with an unexpected visitor. Meanwhile, Davina makes a surprising connection, and Marcel makes Rebekah an enticing offer that leaves her torn.

Rebekah, facing a difficult decision, turns to Father Kieran for guidance. Elijah struggles with the consequences of a recent fallout with Klaus. Hayley remains by his side but is soon drawn away by a mysterious figure who sheds some light on her past. Meanwhile, a frustrated Camille struggles to make sense of a cryptic message she's come across. Finally, when an unsuspecting Marcel uncovers some upsetting information involving Klaus, a confrontation ends in a surprising twist.

Marcel, deeply conflicted by recent events, is surprised when Klaus opens up to him about some of his past indiscretions. Camille tries to make sense of cryptic messages she's come across and is disturbed when she gains some insight into Klaus' past. Meanwhile, in a surprising turn of events, the human faction takes matters into their own hands, resulting in a unhappy confrontation. Elsewhere, when Hayley learns of a plan to harm the werewolves in the bayou, she turns to Elijah and Rebekah for help. After heading to the bayou, they run into a werewolf named Eve, who has information that leads them to a shocking discovery.

As the French Quarter prepares for its annual celebration of the Casket Girls Festival, Cami suffers through as Davina attempts to free her of Klaus' mind compulsion. Elijah and Marcel form an unlikely alliance as Klaus sets his plan in motion to get Davina back. Once it's known that Davina is missing, Sophie gets in on the hunt to track her down. Meanwhile, Hayley is forced to make a tough decision after receiving an unexpected phone call, and Rebekah sets her own plan in motion when she enlists the help of someone from Marcel's past.

When Davina becomes unhappyly ill and the repercussions soon begin to affect the entire French Quarter, Marcel, Klaus, Elijah and Rebekah rush to find out what is going on. Sophie approaches the others with some startling information about the Harvest Festival and presents a drastic plan to save Davina. Elsewhere, Hayley is racked with guilt as she comes clean to Elijah about her role in Sophie's plan. Last, a sequence of unforeseen events sends shockwaves through the French Quarter.

Marcel, still angered by recent events, refuses to help Klaus when a gruesome discovery is made in the Cauldron. Rebekah is on alert when she uncovers the remnants of a sacrifice down by the docks and immediately realizes that it's the work of a dangerous warlock from their past. Meanwhile, when Elijah gets some information that Rebekah may be in trouble, he and Hayley set off to find her. At Rousseau's, Cami comforts Marcel, who opens up and shares some details of his past with her, but things quickly spiral out of control when an unexpected visitor shows up. Finally, a unhappy confrontation ensues when Klaus faces off against a powerful force with an unmatched advantage over him.

At the re-opening of St. Anne's Church, Father Kieran finds himself in a great deal of trouble after a run-in with a witch from his past. Marcel and Rebekah grow concerned when the reemergence of someone they once knew threatens to expose secrets they've kept buried for nearly a century. Elsewhere, Sophie is shocked when a discovery is made at the cemetery, but she soon realizes things may not be as they seem. With the full moon looming, Hayley lets Rebekah in on her plan to throw a party for her werewolf clan, but things take a dangerous turn when uninvited guests arrive. Meanwhile, Cami is conflicted when she makes a difficult decision involving the safety of Father Kieran, and Elijah finds himself facing his own dilemma when he has to choose between Hayley and his siblings. Finally, when one of his plans fails, Klaus takes drastic measures in the Cauldron, resulting in dangerous repercussions that affect everyone involved.

When Rebekah finds herself locked up in the sanatorium where she worked in 1919, she realizes a witch named Genevieve is back to seek revenge and to reveal dark secrets that would destroy Rebekah if exposed. A distraught Elijah turns to Marcel and Hayley for help when one of his decisions puts Klaus and Rebekah's lives in danger. With time working against them, Marcel realizes he may hold valuable information that could lead them to Rebekah and Klaus, but revealing it will almost certainly result in deadly consequences.

In a series of flashbacks to 1919, Klaus opens up to Cami and reveals details of the devastating secret Rebekah and Marcel were trying to keep from him. Elijah forms an unlikely alliance with Monique and asks for her help in locating Sabine Elsewhere, Thierry is reluctant to get involved when Marcel and Rebekah approach him with a plan to take down the witches. Meanwhile, in the bayou, Hayley is at her wits' end and holds Sabine hostage in an attempt to get information that will reverse the curse on Phoebe's werewolf clan.

Despite Klaus' rage, Elijah is determined to protect Rebekah while the three of them are trapped in the City of the Dead cemetery by a witch's boundary spell. Klaus and Rebekah trade bitter accusations until Elijah steps in to reveal a long-held secret from the family's past. Meanwhile, Marcel races to free Rebekah, ultimately finding himself forced to make a deal with Genevieve. Finally, Rebekah and Hayley connect over their shared concern for Hayley's unborn baby.

After accusing Klaus of doing nothing while their control over the Quarter crumbles, Elijah makes a move to take matters into his own hands. He receives an intriguing offer of support from Francesca, a beautiful woman from a powerful New Orleans family. In an attempt to bring the warring factions of the city together, the Mikaelsons throw an extravagant party, where Klaus offers Jackson a tempting deal, Elijah and Hayley share a dance, and a unhappy fight comes to a surprising end. Finally, even as Marcel works on a new path to power, he continues to help Cami deal with her Uncle Kieran's tragedy.

Genevieve asks Elijah to allow her coven to publicly celebrate a traditional feast day, where members of the community offer the witches gifts in return for blessings. Monique and Genevieve disagree over what the ancestors want from them, and Genevieve reveals her plan to build the witches power. When Elijah focuses his attention on restoring their home to its former glory, Klaus accuses him of doing it only to impress Hayley. Next, Klaus sets a new plan in motion by finding Cary (guest star Jesse Boyd), a werewolf from his own line, and sending him off to find a missing piece of family history. Marcel lets Thierry in on his new plan to rebuild his power, but Diego has his own ideas about the future. At the Feast of the Blessings, Monique and Genevieve try to use the ceremony to teach Davina lesson, but Klaus intervenes and gives Davina a surprisingly important gift. While Hayley struggles to decide where her loyalties should lie, the ceremony explodes into violence.

Desperate to help Kieran, Cami insists on an unconventional treatment, but her good intentions lead Kieran to a unhappy episode. After Klaus and Elijah disagree over the best way to handle the Crescent Wolves, Elijah makes a trip to the bayou, where he is witness to a horrific explosion that only adds to the hatred and mistrust among the communities. While Jackson and Elijah work to save the wounded, Hayley learns a surprising piece of her family history from Marcel.

Hayley confronts a surprising enemy as she and her unborn baby fall into peril during a celebratory wake to honor a fallen member of the community. In order to save Hayley, Klaus and Elijah enlist the help of Genevieve who struggles to maintain control over Davina and the other young witches. Cami tells Marcel that Francesca is determined to find a mysterious key that may unlock a family secret. Meanwhile, as Klaus suffers from nightmares of his father Mikael, he is forced to examine his troubled relationship with his own adoptive son, Marcel.

Klaus and Elijah enact a plan to collect the sacred stones needed by Genevieve in order to forever change the fates of Hayley and the werewolf community. Realizing that Klaus' plan will lead to the extermination of all French Quarter vampires, Marcel rallies an army determined to take down the Mikaelsons and regain control of the city. Davina warns Josh to leave town as she is forced to make a fateful decision that will turn the tide of war. Meanwhile, Francesca threatens Cami, who attempts to decipher a code that results in a surprising revelation among the city's factions.

As the baby's due date draws near, Klaus and Elijah embark on a search for Hayley, while Hayley herself is determined to do whatever it takes to keep her unborn baby safe and away from the witches. Francesca takes a meeting with Oliver and Jackson to determine the future of the werewolves in New Orleans. In the aftermath of a surprising attack on Marcel and his vampires at the compound, Davina and Cami join resources to take down Klaus. Finally, in a desperate move to protect those most important to him, Klaus makes a heartbreaking decision.