KATHERINE RETURNS WITH A VENGEANCE — Picking up on the same night as last season's finale, Elena arrives home to a nightmare as she discovers Uncle John's and Jeremy's fate. At the hospital, Sheriff Forbes is comforted by Matt, Bonnie and Damon while she waits to hear if Caroline will survive the car accident. After a confusing conversation with Elena and Jenna about the night's events, Damon is the first to realize that Katherine has returned. Katherine's arrival sends Stefan and Damon on a path to find out what she wants, why she's back, and how much of a threat she is to the people they love. Meanwhile, still reeling from his father's death, Tyler is surprised when his charming and mysterious uncle, Mason Lockwood, arrives to console the family.
- Antagonist: Katherine Pierce.
- This episode marks the last time Caroline is human on the series.
- Katherine meets Matt, Tyler, Bonnie and Caroline in this episode.
- Katherine becomes a series regular as of this episode.
- This is the first episode that Caroline and Katherine appear in the final scene together.
- Since Katherine appears in Caroline's bedroom at the end of this episode, it implies that Katherine got herself invited into her house posing as Elena. Meaning Katherine may have been in Mystic Falls earlier than is known.
- This episode marks the first appearance of Mason Lockwood. The show's first werewolf.
- This is the first episode of Season Two.
- This is the first episode of the first chapter of Season Two, The Katherine Chapter.
- Jeremy Gilbert - broken neck, killed by Damon Salvatore but resurrected by his ring.
- Caroline Forbes - suffocation, killed by Katherine Pierce but returns as a vampire since she had Damon's blood in her system at the time of her death.
- During the wake at the Lockwood mansion, both Damon and Katherine pick and eat fruit from the buffet table. Damon has eaten human food before on the show (he steals Elena's pickle in "Bloodlines"), but this time the parallels between Damon and Katherine are even more evident. The fact neither of them need to eat human food but do anyway indicates the same hedonism that L.J. Smith gave Damon in Dark Reunion.
- This is the first season premiere to not feature Alaric, since joining the show mid-way through season 1.
- Episode name was known on July 12, 2010 thanks to Ian Somerhalder's twitter picture.
- Julie Plec said: "Stefan and Damon will know within the first 15 minutes of the first episode about Katherine. Damon realizes he was duped, and Stefan comes face-to-face with Katherine. The fun of it is how Stefan responds to the moment, as opposed to how Damon responded to the moment."
- Elena's house number is 2104 Maple Street.
- This episode had about 3.35 million viewers in USA.
- This is the first season premiere to not feature Vicki, but feature Katherine.
- Mason meets Tyler and Jeremy in this episode.
- When news of new character Mason Lockwood emerged, fan and media speculation on casting included popular picks of Milo Ventimiglia, Skeet Ulrich, Jason Dohring, Brian Austen Green, and Gale Harold. Ultimately the role went to Taylor Kinney.
- Mads Langer's track "The River Has Run Wild" (featured during the Damon and Katherine scene at the boarding house) was recorded especially for this episode.
- "The Return" is also the episode title of the nineteenth episode of the first season of Once Upon A Time.
- Elena: "Katherine was in this house, that means that she's been invited in. What are we going to do?"
- Damon: "Move."
- Stefan: "What happened tonight when you thought she was Elena?"
- Damon: "To risk another frown line encroaching on a very crowded forehead... We—kissed."
- Elena: "And you thought it was me?"
- Stefan: "What do you mean you kissed?"
- Damon: "Well, you know when two lips pucker and they go—" (makes kissing noise)
- Katherine: "We haven't officially met. I'm Katherine."
- Bonnie: "I know who you are."
- Katherine: "Of course you do. You're the best friend right? I've been putting all the pieces of Elena's life together. Isobel told me it was a bit of a puzzle. I do know who Jenna and Jeremy are and I've met that delicious ex-boyfriend Matt, who's sweet on Caroline and then there's you. The vampire-hating Bennett witch. Did I do good?"
- Stefan: "You haven't changed at all, have you?"
- Katherine: "But you have. You're stronger, meaner, sexy."
- Stefan: "Don't flirt with me Katherine. I'm not Damon, I haven't spent 145 years obsessed with you."
- Katherine: "You wanna know why I'm here, Stefan? I came back for you."
- Stefan: "Well, the problem, Katherine, is that I hate you."
- (Katherine stabs Stefan with a pole)
- Katherine: "You hate me, huh? That sounds like the beginning of a love story Stefan, not the end of one."
- Damon: "I kissed Elena."
- Stefan: "Because you feel something for her, because you actually care. And I'm not gonna let Katherine come in here and destroy that part of you that is finally, after all of this time, willing to feel something. She will try to break you. She will try to break us. And how we respond to that will define us. It's our choice."
- Damon: "I just need the truth just once."
- Katherine: "Stop. I already know your question and it's answer. The truth is... I've never loved you. It was always Stefan."
- Stefan: "He saw the ring, that's why he did it. He knew."
- Elena: "He didn't see the ring."
- Stefan: "It's Katherine. She got under his skin. She undid everything that was good about him."
- Elena: "There's nothing good about him, Stefan—not anymore. He's decided what he wants. He doesn't want to feel, he wants to be hated. It's just easier that way. He got his wish. I hate him Stefan."