The Vampire Diaries.

Three: The End of the Affair.

Klaus and Stefan arrive in Chicago, where Stefan is reunited with a vampire who hasn't really moved on from her interest in him decades earlier. In a flashback to Chicago in the 1920s, Stefan comes face-to-face with a shocking chapter from his wild past. After Damon gets a tip on Stefan and Klaus' whereabouts from an unexpected source, Damon and Ellie follow their trail. Back in Mystic Falls, Tyler is concerned about Caroline and turns to Elena and Sheriff Forbes for help.

Later, Damon poured himself a drink and pulled out his ringing phone, seeing an unknown number...

Damon: "You're interrupting my drink."

Unknown: "You miss me?"

Damon: "Katherine. Where are you?"

Katherine: "Lurking outside your window, pining away."

Damon: "What do you want?"

Katherine: "I'm homesick. What have I missed?"

Damon: "Stefan's still Klaus' little prisoner, and Ellie still thinks she can save him... which I think is kind of true. And no one's thought about you since you left."

Katherine: "And what about you? Now that you've given up on your brother... I'm sure you're plotting some sort of way of making a move on Elena, just to rub it in Ellie's face."

Damon: "No. Because, frankly, Katherine, I actually like Ellie. She's my friend. And for your information, I didn't give up on him. I just don't know where he is."

Katherine: "Mm."

Damon: "But you do. Are you stupid enough to be trailing them?"

Katherine: "A hybrid who wants me dead and his sidekick who's off the rails? I couldn't be further away."

Damon: "In your language, you know where they are."

Katherine: "All I know is that Klaus pitched a fit once his hybrids didn't work. Now he's looking for answers."

Damon: "How do you know that?"

Katherine: "Spend 500 years running; there will be a few people looking out for you."

Damon: "Is that what you're doing? Looking out for my brother? Because I've told you before, it's creepy..."

Katherine: "Maybe, maybe not. I'm conflicted."

Damon: "Where are they, Katherine?"

Stefan and Klaus pulled up in a car...

"Welcome back to Chicago, Stefan."

"What are we doing here?" Asked Stefan.

"I know how much you loved it here. Bringing back memories of the good old ripper days?"

"Black out most of it. Lot of blood and a lot of partying. The details are all a blur." Stefan tells him.

"Well, that is a crying shame. The details are what make it a legend."