Caroline wakes up in bed gasping. She's alone in her hospital room, but it's soon obvious to us, and to her, that she's transitioning.
The next day, after feeding on a nurse and wiping her memory, Caroline escapes the hospital and goes looking for her friends.
Elena had hoped that the Mystic Falls carnival would help restore things to normal, at least temporarily. Yeah, right.
Caroline confronts Damon and tells him that she now remembers everything he did to her before she died. She pushes him to the ground with her newfound strength, relays Katherine's message, and leaves.
Damon wants to stake Caroline, but Stefan and Elena won’t hear of it. They want to help her transition. Damon plots to kill her.
Why? Because he says it will end badly at some point anyway. Lo and behold, he then finds Caroline next to a dead body.
She killed some poor stiff who was working to set up the carnival. It was just not the guy's day. He'd already gotten in a fight with Tyler (more on that in a second).
Damon says that he can help her, but his plan to murder her is thwarted by Stefan and Elena intervening at the last second.
Then Caroline sees that someone else was watching the whole thing: Bonnie, who is horrified to see her friend this way.
Stefan tries to clean her up and tells her she will have to fight the urge to kill.
Damon buries the body of the guy Caroline killed, but when he returns to the carnival, Bonnie unleashes some crazy spell, effectively paralyzing him on the ground while dousing him in gasoline and setting him on fire. Witches ...
But, before Damon can meet his end, Elena breaks Bonnie’s concentration and convinces her to walk away.
It's not Damon's night either. When he gets home, Jeremy is waiting for him, having laced his liquor with vervain and fashioned a stake. It's Jeremy, though, and he ends up telling Damon his plan without actually doing anything. Then he leaves.
Meanwhile, Tyler is starting to realize that there’s something extraordinary about Uncle Mason. Mason is very interested in his nephew’s anger issues.
Damon, who happens to be in the other room meeting with the head of the council, overhears the Lockwoods' curious conversation and is determined to find out what they are.
At the carnival, Damon convinces Stefan to take on Mason in an arm wrestling match. Mason wins, which surprises Stefan, who says Mason's strength is definitely not human.
Stefan is still skeptical, but Damon won't let up. He convinces the carnival guy to pick a fight with Tyler, and when they start brawling, Mason steps in to end it.
Tyler sees his uncle’s eyes glow as he pulls off some insane kung fu moves that are definitely above human skill level. Mason claims he was just using Brazilian martial arts, but Tyler knows something is up.
Earlier, Mason had been asking if he’d seen an heirloom moonstone in the mansion. Tyler said no, but in reality, he knew where it was. At the end, he secretly pockets the beautiful stone.
Caroline reunites with Matt, and resists her urge to make him dinner. She's learning to control her vampire powers already.
After all that, Stefan attempts to salvage just a little bit of normalcy. In the early hours of the morning, he appears in Elena's bedroom and whisks her off to the carnival grounds, where he starts up the ferris wheel, carries her to the top and kisses her.