After spending the past four months coping with the loss of Damon in an unconventional and potentially dangerous way, Elena has returned to Whitmore College for the start of sophomore year. Unable to move on, Caroline is desperate to find a way to reverse the anti-magic spell the Travelers have put over Mystic Falls and grows frustrated when her calls to Stefan go unanswered. Tyler, who is human once again, has a run-in at a football tailgate that tests his ability to control his anger, while Matt worries that Jeremy is dealing with the loss of Bonnie in a self-destructive way. Alaric, who is struggling to adjust to his new life as a vampire, finds himself in an awkward situation when he meets Jo, a beautiful doctor at the university hospital. Last, while everyone believes Stefan is off tracking a lead to get Damon and Bonnie back, Elena is shocked when she learns the truth of what he has really been up to.

Knowing she needs to come to terms with the loss of Damon, Elena turns to Alaric to help her move on with her life. Enzo convinces Caroline to join him as he tracks down a lead to get Damon and Bonnie back, but Caroline is shocked when they make an unexpected detour and uncover what Stefan has been up to. Meanwhile, Matt worries about Jeremy who is spending time with Sarah (guest star Gabrielle Walsh), a mysterious girl who has recently arrived in Mystic Falls. Elsewhere, Tripp (guest star Colin Ferguson), leader of the community protection program, makes an interesting confession to Matt about his connection to the town. Lastly, with the Other Side destroyed and gone for good, Damon and Bonnie reluctantly band together to uncover the mystery of where they are and how they are going to get back home.

In an attempt to bring some fun back into their lives, Elena persuades Caroline to meet her at the swimming hole where she plans to introduce her to Liam. Tyler, still working on controlling his anger issues, asks Liv for a favor and is surprised when she makes an unexpected confession. Stefan arrives back in Mystic Falls looking for Enzo and is caught off guard when he notices a strange change in Elena. Meanwhile, at the lake, Enzo's actions cause Matt to make a startling revelation, and Jeremy makes a discovery about the anti-magic spell that could potentially put Elena's life in danger. Elsewhere, Damon and Bonnie stumble upon clues that lead them to believe they're not alone.

When Damon and Bonnie realize that uncovering a time in Damon's past may provide clues to finding their way home, Damon is forced to relive one of the worst days of his life. After an awkward run-in with Jo at the hospital, Alaric steps in to help Jeremy get his life together and cope with the loss of Bonnie. Elsewhere, Stefan attempts to show Elena what it's like to start over and create a new identity, while an unsuspecting Matt finds himself in a disturbing situation when Tripp lets him in on a dark secret. Lastly, Stefan, who is desperate to regain some normalcy in his life, is stunned when an unexpected visitor shows up.

With Homecoming around the corner, Elena invites Liam to attend a party at the corn maze with her. Instead of attending the homecoming festivities, Caroline is preoccupied after Stefan shows up unexpectedly and needs her help cleaning up a mess created by Enzo. Heeding Elena's advice to be more social, Alaric reluctantly attends the party, but a devastating accident quickly leaves him and Jo rushing to save lives. Elsewhere, Tyler finds himself in a dangerous position when his werewolf curse is put to the test, and an emotionally embattled Stefan comes clean to Caroline about his intent to move on from Mystic Falls. Lastly, Damon and Bonnie make an important discovery that affects their quest to get back home.

When Alaric realizes that Jo can't be compelled, he asks Elena to do some digging into her background. After learning that Enzo has been captured by Tripp, Caroline teams up with Matt and Stefan to rescue him before Tripp learns their true identities. Armed with some new information about her past, Sarah breaks into Tripp's office and is surprised when she finds Matt there, doing some investigating of his own. Meanwhile, Elena is forced to deal with the consequences of her actions, and Jeremy hits rock bottom, lashing out in a destructive way. Lastly, Damon is determined to take matters into his own hands when he receives some upsetting news.

When the past comes back to haunt her, Elena is forced to face her problems head on. After a night out at the annual Whitmore Medical Center Fundraiser, Jo opens up to Alaric about her own tragic past. Meanwhile, Stefan, Matt and Enzo resort to extreme measures when Tripp withholds information about his vampire-hugging operation, and Caroline is in a race against the clock when Sheriff Forbes gets caught in the middle of a dangerous plan. Elsewhere, Tyler and Liv grow closer, and Damon stumbles upon a startling clue that renews his hope.

As Caroline and Elena prepare to host Friendsgiving at the dorm, they receive some hopeful news from Alaric and Stefan, who have traveled to Portland to gather some information regarding the Gemini Coven. Tyler is determined to help Liv after she and Luke reveal some disturbing information about their witch lineage and the impending plans their coven has for them. Meanwhile, dinner takes a drastic turn when Jo, who has revealed some painful details about her past, finds herself fighting for her life, leaving Alaric scrambling to help from a distance. Finally, Kai makes a dangerous discovery that brings him one step closer to his release.

Damon finds himself in hot water after he carries out a plan that requires Alaric's unwilling participation. When Elena shares some hopeful news with Jeremy about Bonnie, she is caught off guard by his reaction. Liv helps Damon and Elena with their plan to get Bonnie back, but when things take an unexpected turn, she's left with a difficult choice to make. Elsewhere, Matt takes matters into his own hands when Enzo's actions cross the line, and Kai's existence continues to be a dangerous threat.

With the holidays approaching, Bonnie attempts to replicate her favorite traditions, while reminiscing about happier times with her friends. Not able to return home to Mystic Falls for her favorite time of the year, Caroline is surprised when Sheriff Forbes brings the holidays to her at Whitmore College. Meanwhile, after discovering that Jo has gone missing, Alaric turns to Damon and Elena for help, while Liv and Luke find themselves at odds when Tyler approaches them with a risky plan. Elsewhere, Jeremy helps Matt carry out a plan to take down Enzo but grows concerned when Matt takes things too far. Lastly, Stefan is forced to break some devastating news to Caroline.

More powerful than ever, Kai holds Elena captive while he learns to control his newly acquired magic. At the Salvatore mansion, Liv and Alaric try to prepare Jo for the impending merge ceremony with Kai, but they quickly realize Jo is weaker than they thought. After bringing Sheriff Forbes home from the hospital, Caroline travels with Stefan to North Carolina in search of a cure for her mother's cancer. Meanwhile, Stefan, who has his own intentions for traveling to North Carolina, is caught off guard when Enzo shows up demanding to know what Stefan is hiding. Lastly, when Damon discovers Elena has been kidnapped by Kai, he is forced to rethink his strategy after an unexpected visitor throws a wrench into his plan.

When Liv and Luke's father arrives to town to celebrate their birthday, they try and convince him to let Jo and Kai take their place in the merge ceremony. After Tyler finds out that the merge is happening sooner than he expected, he urges Liv to let him talk to her father. Meanwhile, after Caroline's plan to cure her mother takes an unexpected and devastating turn, Elena, Stefan and Damon gather at the hospital, while Jo attempts to save Sheriff Forbes' life. Lastly, with the merge set to take place, Damon's risky plan quickly sends things spiraling out of control, forcing one of the twins to take matters into their own hands.

Determined to celebrate Bonnie's birthday, Elena convinces Jeremy that it's what Bonnie would have wanted. After piecing the broken ascendant back together, Elena, Jeremy and Damon attempt to send Bonnie a message, but the situation turns dire when they make an unsettling discovery. Meanwhile, after uncovering Stefan's secret about his great-niece Sarah Salvatore, Enzo enlists a reluctant Matt to help interfere with her life. Elsewhere, Stefan keeps a close eye on Caroline as she unconventionally attempts to cope with everything going on around her. Lastly, realizing it might be time to move on with his life, Jeremy contemplates leaving Mystic Falls for good.

It's Jeremy's last day in Mystic Falls and Elena puts on a brave face as they reminisce about their past. Stefan and Caroline find themselves growing closer as they prepare Caroline's family cabin for her mother to live out her final days. While packing up her office, Sheriff Forbes turns to Damon for help solving one of her remaining open cases involving Elena's parents. Elsewhere, when a unhappy confrontation with Enzo leaves Jeremy wondering whether he should leave or not, Matt finds his own life on the line after Enzo lures him and Sarah Salvatore into his dangerous plan. Lastly, Caroline rushes to the hospital after learning her mother has taken a turn for the worse.

After assigning tasks to each of her friends, Caroline attempts to deal with her current situation as reality begins to set in around her. While spending the day with Caroline, Elena grows concerned when she starts noticing a strange change in her behavior. Meanwhile, Alaric becomes wary when Kai, who has begun experiencing unexpected consequences from the merge, turns to Jo, desperate for her help. Elsewhere, while Bonnie finds herself in an unfamiliar situation, Matt and Tyler contemplate a major life change. And when Damon offers Caroline advice on how to cope with everything going on around her, it forces him to revisit painful memories involving his own mother.

After shutting off her humanity following the passing of her mother, Caroline gives her friends an unexpected ultimatum. Not knowing how to handle the new Caroline, Stefan's attempt to intervene sets off a dangerous chain of events, leaving him and Elena in a race against the clock. Meanwhile, after seeking answers from Kai about the prison world, Damon's world is turned upside when he learns some devastating news about his mother Lily. Elsewhere, Enzo finds himself becoming increasingly intrigued by Sarah Salvatore, and Bonnie begins to struggle with the effects of being back in the real world.

With the help of Bonnie and Kai, Damon and Elena set forth a plan to rescue Damon's mother Lily, who is trapped in the 1903 prison world. Meanwhile, when Caroline's plan for Stefan backfires, she is left to pick up the pieces. Elsewhere, back at Whitmore College, Enzo and Alaric's attempt to reel Caroline back in doesn't quite go as planned when they realize they're outmaneuvered. Lastly, an unexpected gift from Bonnie leaves Damon shaken to his core.

With their humanity turned off, Stefan and Caroline begin wreaking havoc at Whitmore, leaving Damon to come up with a risky plan involving Lily. After rushing to help Jo treat victims of Stefan and Caroline's latest hugging spree, Elena discovers Jo is pregnant, prompting her to reevaluate her own life as a vampire. Meanwhile, when Sarah boldly turns the tables on an unsuspecting Enzo, he is forced to open up about his tragic past. Lastly, at Scull Bar, a twisted round of karaoke leaves Tyler and Matt in a dangerous situation.

Wrestling with whether or not to tell Elena about the cure, Damon brings up their future together and what life would be like if they weren't vampires. Meanwhile, it's all hands on deck when attempts to stop a humanity-free Caroline doesn't go as planned. Elsewhere, when Bonnie discovers that Damon has betrayed her trust, she takes matters into her own hands, setting off a chain of events that leaves Damon dealing with the fallout. Lastly, after being forced to face his traumatic past, Enzo sets out for answers and is surprised when he learns the truth about the day he was turned into a vampire.

As Alaric and Jo reluctantly participate in their bachelor and bachelorette parties, Damon and Elena discuss the ramifications from an impulsive offer that Damon makes. Unsure of what to do, Elena turns to Bonnie and Jo for advice, but is left conflicted when Bonnie raises some unanticipated concerns. When Enzo realizes Lily is on a dangerous downward spiral, he asks Stefan to help intervene before it's too late. Lastly, fed up with the supernatural threats that plague their town, Matt takes his frustrations out on Tyler, while Alaric considers a life-changing piece of advice.

It's Alaric and Jo's wedding day and Elena and Bonnie do their best to help a stressed out Jo with the last minute preparations. After uncovering some life-changing news that Damon has been keeping from him, Stefan takes his brother on a road trip to give him some perspective on his future with Elena. Elsewhere, when Caroline returns to Mystic Falls after dealing with the fallout of her humanity-free rampage, she begins making amends with her friends and comes to a realization about her and Stefan's prospects of being together. Finally, when Bonnie begins having vivid nightmares that Lily is coming after her, she enlists Matt's help in taking Lily down.

In the aftermath of Alaric and Jo's powerful nuptials, things take a dramatic turn when an uninvited guest shows up, leaving Elena in terrible jeopardy. Despite Matt's advice to leave town to protect herself, a defiant Bonnie takes matters into her own hands after finding herself on the receiving end of a twisted plan. As Stefan and Caroline reach an emotional crossroad in their relationship, a reunion with Liv leaves Tyler faced with a decision that could change his life forever. Meanwhile, Lily's reckless actions cause Stefan to realize the lengths to which his mother will go to reunite with her "family". Finally, after a devastating chain of events, Damon is forced to make the most difficult decision of his life.