Even as Nadia is going back over the memories of her centuries long search for Katherine, Stefan, Caroline and Matt figure out a new plan to save Elena's life. Jeremy and Bonnie need Liv's help again. Damon is determined to get revenge on Dr. Maxfield. Caroline and Tyler work out a new understanding. Bonnie discovers a horrifying secret that endangers her friends.moreless
Since Dr. Wes injected Damon with the serum his behavior has gone from bad to worse. Stefan feels bad telling Damon never to return to Mystic Falls so he sets out to find him with Elena tagging along. Once again Dr. Wes asks the Travelers for help when he decides to test the friendship between Damon and Enzo. Matt recruits Caroline and Tyler to help protect Elena ending with a violent confrontation. As Stephan later tries to console unhappy Caroline, their talking leads to a shocking realization.moreless
After receiving some shocking news Stephen attempts to restore order in both his worlds by striking a deal with Jedikiah.
Cara and Russell contend with a new break-out and must also deal with an ULTRA trap.
Meanwhile Jedikiah is closer to developing a secret technology that could change his future.
Rebekah struggles with memories of her past while Klaus is informed of the reason his father appeared in N.Orleans back at 1919. Elijah will have to figure out a riddle to accomplish his goal and later choose between letting Klaus exact his revenge or save his sister from the hybrid's wrath.moreless
Whitmore College holds its annual "Bitter Ball" for broken-hearted students, which Caroline persuades Elena and Bonnie to attend. Bonnie meets up with Liv who seems to be playing her hand at witchcraft. Matt's relationship with Nadia bothers Tyler. Stefan speaks to Damon and Enzo after making a troubling discovery. Dr. Maxfield gets a new benefactor for his struggling research project. Damon and Enzo use violence to induce Bonnie and Jeremy to help them with their revenge plans but things don't go as planned.moreless
Stephen is upset with Jedikiah for going back on his word, forcing him to face The Founder.
In order to protect Astrid, Stephen must make a deal to bring in a powerful break-out and elsewhere John clashes with Cara which forces her to issue a harsh punishment.
Sophie is shocked by the resurrection of Monique Devereux at the cemetery. Father Kieran finds himself in a great deal of trouble after being marked by a Witch from his past at the re-opening of St. Anne’s Church. Diego contacts Klaus after finding Papa Tunde’s sacrificed body at the Cauldron. It is clear that the Witches have declared war on the Original Vampires.
Worried about Hayley’s safety, Elijah instructs Rebekah to take Hayley to the plantation house. With the full moon looming, Hayley lets Rebekah in on her plan to throw a party for her werewolf clan at the plantation house, but things take a dangerous turn when uninvited guests arrive.
Marcel approaches Sophie and Monique with a plan to resurrect the remaining witches sacrificed from the Harvest. Meanwhile, Camille 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, Klaus takes drastic measures to find the resurrected Witches resulting in dangerous repercussions that affect everyone involved.moreless
Nadia has figured out a way to keep Katherine permanently in Elena's body but first she needs to find Katherine's body which has mysteriously disappeared. Enzo comes to Damon with a grisly present and wants them to carry out an act of revenge but Damon tries had to do the right thing. Matt throws a party at which Caroline makes a stunning admission to Elena. Caroline's confession forces her then to face the consequence of her actions with Stefan and Tyler. Aaron decides to start a new life. When Elena finds herself in a life threatening position, she doesn't have much time to figure out how to save herself.moreless
With her impending death, 500-year-old Katherine reminisces about her life and the night she gave birth in 1490. Stefan informs Elena, Caroline and Bonnie that Katherine doesn't have long to live. Damon, Matt and Jeremy talk about Katherine's infamous moments. Stefan and Elena are forced to help Nadia save her mother. Caroline indulges in some scandalous behavior. Katherine and Elena share a moment of bonding.moreless
Stephen and his fellow ULTRA trainees are given a test by Jedikiah to determine their worthiness as Agents but not everyone is happy to work as a team.
Cara is faced with a visitor from her past and John works with a new breakout while Russell is sent on a dangerous recon mission that could force a clash between different groups of Tomorrow People
Davina loses control her powers and becomes violently ill and sends shockwaves, winds and rainstorms through the French Quarter. Elijah approaches the Sophie for answers and is informed that the Harvest Festival needs to be completed to save Davina. Hayle angers Elijah when she comes clean to about her role in Sophie's plan to complete the Harvest by consecrating Celeste dubois’s remains. Meanwhile Marcel takes Davina into hiding to prevent the Harvest ritual from being completed.
Damon asks for Stefan's help to find Elena. The brothers visit Aaron and Stefan is shocked of what Damon knows. Dr Wes is trying to stop Damon and thus releases a secret weapon, forcing Damon to face his past. Dr Wes confesses information to Elena about the history of Whitmore College as well as his goal. Katherine turns to Matt for help and she realizes that the solution to her problem may be Nadia.moreless
When John finds himself in a dangerous situation Stephen finds he is unable to help without revealing his duplicity to ULTRA. Also not satisfied with the answer he discovered about his father's death Stephen decides to take drastic action to find the truth with help from his fellow Tomorrow People.
Cara and Russell negotiate a trade with Jedikiah which ultimately makes Jedikiah take a big risk.
Stefan helps Katherine in order to deal with his pain until Caroline finds another way. Elena tries to fix things with Caroline and gets very concerned about Damon that she asks Aaron for help. Damon reveals aspects of his dark life to Elena and she tells him what she has just learnt about her family. Aaron takes a desperate path after a conversation with Dr. Wes.moreless
Stephen is determined to uncover what he hopes is the key to finding his father, and crafts a plan with The Tomorrow People that involves getting inside Jedikiah’s head. Meanwhile, Cara and Russell encounter an uninvited visitor in the subway tunnel base.
Stephen takes a risky opportunity and snoops around ULTRA.
Elena and Caroline decide to throw a party, but they are interrupted when Jesse requests Caroline's help. Damon gets information from Wes when Elena asks him to. At the party Elena finds out she is a lot like Aaron and Caroline is more and more concerned about Jesse. Katherine does a favor to Matt and helps Stefan coping with the events of the summer. Bonnie tries to deal with how things currently are and Damon makes a discovery about the secret society.moreless
After Stephen decides to have some fun with his newfound powers, Jedikiah takes extreme measures to ensure it doesn't happen again.
John feels tension between himself and Cara after he and Russell return from their trip while Stephen decides to try and handle a dangerous new breakout on his own but finds himself in over his head and needing help from his fellow Tomorrow People.
Stephen becomes even more determined to find out what happened to his father after having a moment of clarity about him.
Damon and Elena try to describe Amara's situation to Stefan. While Katherine gets disturbing news from Dr. Wes, Nadia is searching for her in Caroline's dorm. Jeremy's and Bonnie's discussion with Amara makes them hope. When Silas does not keep a promise, Damon turns to Tessa for assistance. Stefan makes a confession to Damon and Elena.moreless
Stephen and Russell head out for a night of fun only to run into a potential new breakout. They report back to John and Cara about the discovery but want to keep a low profile from ULTRA.
Russell learns of his father's death and struggles with the decision of whether or not to return home. John volunteers to go with him to keep him out of trouble.
Meanwhile Jedikiah has a secret that could destroy his career.
Silas promises to get something done in exchange for Damon's and Elena's assistance. Tessa announces her new plan to Stefan, only to realize Silas is ahead of her. Katherine tries to persuade Caroline to give her a place in their dormitory room. Bonnie is touched by Jeremy's attitude to her situation. Damon is surprised to find out what Tessa's plan is hiding.moreless
After Stephen breaks ULTRA protocol during a training exercise, Jedikiah's mysterious boss insists on meeting him. After learning Jedikiah is unable to help him Stephen turns to John who is only interested for selfish reasons.
Elsewhere Cara and John disagree on a dangerous plan when some of The Tomorrow People become desperate to attend a party in the outside world. And when Stephen again bails on plans with Astrid she decides to find out what he is really up to.
Elena is very touched by a student called Aaron. She and Damon attend the Whitmore Historical Ball as Anne Boleyn and Henry VIII. Dr. Maxfield shares some disturbing information with Elena. Caroline is heartbroken. Nadia reveals her story to Katherine and Damon tries to make a deal with Silas, but things get out of control.moreless
When ULTRA's most wanted man Killian McCrane resurfaces after years in hiding Stephen enlists John's help in tracking him down. John agrees but changes his mind when he learn Killian isn't after Jedikiah as everyone first believed.
Stephen still wants to help but Cara explains the history between Killian and John: A history that brings back memories from John's past and forces him to do something he never thought he would ever do again.
Meanwhile Stephen's mom becomes suspicious of his whereabouts and activities placing him in an awkward position.
While Mystic Falls has its Observance Day in order to honor its dead, Damon and Elena try to help out Stefan, which has the emotional impact of its own on Elena. Matt is worried about his blackouts and tries to find out more about them. Caroline tries to get to know Jesse and Jeremy confesses something that affects Damon greatly. Dr. Maxfield sets a plan that will change everything in motion.moreless
Katherine and Elena convince Damon to help them find Stefan, after they both have the same dream about him being in danger. A mysterious woman called Tessa messes with their plans, reveals things from the past as well as some disturbing news for Damon's future. Meanwhile, Silas reveals the reason he is after Katherine, a search that puts Matt's life in danger and Damon and Elena have to face new facts.moreless
Stephen looks to his fellow Tomorrow People for help when ultra attempts to scan his brain. John refuses to help forcing Cara to help Stephen secretly.
ULTRA and Stephen both search for a new break out who is using his powers to commit crimes. when an ULTRA SWAT team arrives stephen again calls on John, Cara and Russell for help.
John attempts to convince Stephen to spy on ULTRA while continuing the search for his missing father.