This season, Katherine's appearance in Mystic Falls will throw a wrench into the love triangle between Stefan, Elena and Damon, and the other residents of Mystic Falls must choose sides as they fall victim to a new breed of danger. New and unexpected friendships will be forged, allies will become enemies and hearts will be broken. Plus, Stefan and Damon will be forced to face a villain more evil and diabolical than they thought possible.

Life hasn't been the same for Elena since the tragic death of her parents, but she tries to pick up the pieces and provide support for her troubled younger brother, Jeremy. On her first day back at Mystic Falls High School, Elena meets the mysterious new guy, Stefan, and the two seeming lost souls form an instant connection. What Elena doesn't know, however, is that Stefan is a vampire, constantly resisting the urge to taste her blood. But Stefan, it seems, has a greater evil to deal with when his dangerous older brother, Damon, shows up to wreak havoc on the town of Mystic Falls — and claim Elena for himself.

新学期开始前，一辆私家车载着Wilson一家从堪萨斯的小镇去往奢华的比佛利山。Annie（施蕾·葛莱姆斯 Shenae Grimes 饰）和自幼被收养的黑人哥哥Dixon（特里斯坦·瓦尔德斯 Tristan Wilds 饰）对新家与新学校都有着憧憬又有点担心，此次父亲Harry（罗伯·艾斯特斯 Rob Estes 饰）一来是为了照顾昔日好莱坞明星、行事语言夸张的母亲Tabitha、二来是担任子女们周一就要上课的学校新校长。他对子女的严格管教与母亲对孙儿及时行乐享受青春的影响恰成对比。
新学期正式开始，Annie和Dixon和其他新生一样，因为父亲的身份特殊，遭遇同学的嘲笑和故意的捉弄，但阳光的Annie用自己的善良和笑容慢慢赢得了朋友的真心，而Dixon则为了自己的球队梦想而努力。在洛杉矶，在比佛利，这群青春新鲜人自由肆意地活出自己的生活和风格。