Special Guest Star
- Antagonists: Kai and Cade.
- Arcadius is killed by Stefan.
- Katherine becomes the new "Queen" of Hell.
- Kai has absorbed the magic from the Armory before attacking Caroline.
- With Bonnie's help, Josie and Lizzie managed to create a new Prison World for Kai.
- This is the fourth and final episode this season to not feature Matt.
- When Kai grabbed Stefan's hand, he couldn't siphon magic from his body, although Stefan had The Cure in his blood.
- Damon Salvatore - Staked; killed by himself (temporarily)
- Arcadius - Stabbed by his dagger; killed by Stefan
- Mystic Falls, Virginia
- Enzo's Safehouse
- Grove Hill, Virginia
- Bar (present and Prison World)
- Jo was mentioned. She was last seen in Best Served Cold as a corpse.
- Elena was briefly seen in this episode. Her last brief appearance was in Things We Lost in the Fire.
- Katherine was mentioned. She was last seen as a hallucination in While You Were Sleeping.
Behind the Scenes
- "It's been a hell of a ride" is a line from Damon to Elena in season one's Blood Brothers.
- Hashtag during the airing was #KillTheDevil
- "Hello, Clarice" is a reference to The Silence of the Lambs, a film about a serial killer Hannibal Lecter.
- Stefan: "Cade is free... because of me. That's why I have to kill him."
- Damon: "It's suicide!"
- Kai: "You kill the devil, Hell goes along with him."
- Bonnie: "Something's happening!"
- Damon: "You screw this up, we don't know what he'll do to Elena."
- Arcadius: "Your suffering is just beginning."
- Stefan: "No!"
- Caroline: "When were you going to tell me that the girls were asked to leave their preschool?"
- Alaric: "When I figured out how to stop it and could find them another school to go to. There's just nowhere for them to go."
- Caroline: "But you lied to me! You said that the magic and the siphoning was new."
- Alaric: "And I am sorry, but I'm not the only one keeping secrets here. I mean what's up with the flower girl dresses in the box here anyways?"
- Caroline: "Stefan and I are having some issues. I don't know what's going to happen, so I didn't want to be surrounded by all my wedding stuff."
- Alaric: "I'm really sorry to hear that. By why don't we just call someone? I mean, we're not equipped to handle this."
- Caroline: "Who are we going to call? They're not triggered by some magical development or Coven secret, or anything you're going to find in your books. It's probably just us."
- Alaric: "What do you mean?"
- Caroline: "Think about what we've put them through. Splitting up, moving around, everything that happened with Seline. The way they came into this world even. They're sensitive children."
- Alaric: "So we're bad parents?"
- Caroline: "No, but we could do better if we just start trying --"
- Damon: "Sorry, this place had the nearest holding cell. Little help?"
- Damon: "So, you just opted to help me with this homicidal lunatic instead of spending a moment with your fiancé? Care to elaborate?"
- Caroline: "Given what you've just dragged in, I think you should be the one explaining."
- Damon: "Sorry blondie, probably safer if you don't get involved."
- Caroline: "Great, another Salvatore brother freezing me out. Stefan told me that he needed to go on some spirit walk to God knows where to figure out id he wants to be with me."
- Damon: "Hmm. Well in his tiny human brain, I'm sure he thinks he's protecting you. he doesn't believe he's worthy of someone like you Caroline."
- Caroline: "You felt that way about Elena. I need Stefan just as much as she needed you. And Lizzie and Josie need him too."
- Kai: "Ughh... enough about Stefan already. What you guys need is someone who can explain to you what's going on with your Gemini Coven twins. Huh, I think there's someone around here who could help you with that, but I just can't quite put my finger on it. There he is! This guy."