After realizing the downward spiral he was on, Damon decides he's going to turn over a new leaf and that his actions moving forward will do right by Elena. Lily prepares for the arrival of a special figure from her past, while Enzo stands by not sure what to expect. Elsewhere, at Caroline's urging, Stefan comes face-to-face with Valerie
After being reunited with her former love Julian, Lily hosts a dinner party to introduce him to Damon and Stefan and to declare peace between her family of Heretics and the residents of Mystic Falls. Damon and Stefan find themselves at an impasse when they realize they have differing views on how to handle Julian's arrival.
In order to get through to Lily about Julian's manipulating ways, Stefan and Damon confront their mother with painful memories from their childhood. However, when Lily reveals a dark secret she's been harboring for over 160 years, Stefan and Damon are left questioning everything they've ever known about their family. Determined to prove himself to Lily, Enzo comes face-to-face with Julian and challenges him to a duel, but an unexpected twist threatens to complicate things. Elsewhere, Matt finds himself in the middle of a deepening mystery involving the residents of Mystic Falls, and Caroline's world is turned upside down when Valerie reveals some life-changing news to her.
As Julian and Lily throw a party to celebrate Mary Louise and Nora's anniversary, Stefan and Damon set in motion a risky plan to eliminate a new threat posed by Julian. Meanwhile, following a major revelation uncovered by Valerie, Caroline is forced to face her new reality.
With the holidays in full swing, a search for Julian leads Damon and Stefan to a small town outside of Mystic Falls. While managing a holiday toy drive at Whitmore College, Bonnie seeks help from Nora and the two strike up an unlikely friendship. Elsewhere, Caroline does her best to navigate her new life as a pregnant vampire, while Alaric grows concerned that the pregnancy is effecting her more than she's letting on.
After Damon awakes in the Phoenix stone, he has to relive a traumatic experience from the Civil War.
Stefan secretly finds it hard to deal with his own experience in the Phoenix stone as he attempts to help Damon recover and regain his grip on reality.
Stefan attempts to reason with an increasingly reckless Damon and finds out the devastating reason for his brother's strange behavior. Caroline needs Valerie's help after she starts to suffer some dangerous side effects during her pregnancy.
Pregnancy complications leave Caroline's life in danger causing Stefan and Valerie to take some extreme measures.