A girl sits with Ms. Martin, talking about her options for college. She's not really paying attention though. She's re-living the little glimpses of her dreams. She confides in Ms. Martin that she has night terrors and though she usually doesn't remember them come morning, this one she does. Her dream was of a crow tapping on her window in the middle of a rain storm. Upon further inspection she notices something else at her window. She locks the window and tries to get back to sleep but something has already gotten inside. As she tries to re-close the window the chair is pulled out from under her.
She doesn't believe that parts of the dream were fake because the window was sealed shut but she was found on the ground next to the chair. As she gets up to leave, she starts coughing violently. Ms. Martin gets up to help and just in time too. The girl pukes black sludge all over the desk. She picks a crow's feather out of the sludge.
Scott is learning how to administer shots to dogs from animals. "He's little but his teeth are still sharp," will probably come back later. Scott gives the dog back to his owner and goes back to find Deaton examining the nail. It's a talon from a harpy and shouldn't be able to steal Scott's power. Only a beta of his making should be able to but Deaton believes someone is trying to change the rules of the supernatural world.
Stiles, suspicious of Theo, starts telling his father his theories. His father doesn't believe him and tells him to go to school. Stiles notices something different about his father. The end up doing a back-up check on Theo, only to find a speeding ticket. Malia points out that Stiles has many more tickets than that and his father got him out of it. She asks him why he's so suspicious and he responds that he remembers Theo but that the person that came back is not Theo.
Scott arrives at school. Kira meets him at the entrance and they share a kiss. Mason is looking into what attacked him at the end of last season. Liam isn't giving anything away though. When they get to class, there's a girl that Liam remembers from sixth grade. He gets nervous and refuses to sit down. Mr. Yukimura tell him to sit down. He does, straight into a wade of chewed gum.
In biology, Lydia and Kira share a silent conversation. They are confused as to why Scott is in their AP class. Apparently, it wasn't a mistake. Turns out Theo is in the class. There's going to be a huge test in the class the next day, to weed out those who don't belong. Scott wants to be in the class because he wants to get into the best college biology program in Cali.
Liam distracts Mason from the endless barrage of questions by sending him after his soccer team crush. Only to find out, the girl with a grudge on him has the locker next to his. She warns him she's vengeful. In a different part of the school, the student with night terrors, Tracy, is have hallucinations of black blood flowing out of lockers. A doctor starts to crawl out of a locker towards her. Just as it's about to reach her, Lydia comes up to her and pulls her out. Might not be just a dream as there are claw marks in Tracy's locker now.
Theo starts telling Scott and Stiles the story of how he became a wolf. He says he was skating in a neighbors empty pool. It got late and he fell but the board didn't fall with him. From their the wolf charged at him. Stiles wants to know why he didn't become part of that wolf's pack. Apparently, the wolf was Aiden's alpha, the one he and his brother, Ethan, killed. Theo guilt trips Scott about lone wolves not making it and being the same kid from before.
Scott tells Stiles that they're giving Theo the benefit of the doubt. Stiles swears he's right, and so far the track record is 100 percent when Stiles thinks someone is evil, they usually are. Lydia questions her mother about Tracy and Parrish examines Tracy's room. He finds that the skylight is in fact open. He looks through it. Lydia asks if he sees anything. He lies and says no, even though there are a ton of dead crows on Tracy's roof.
Malia's taking her driving test with Mr. Yukimura, where she starts to has flashbacks. It causes her to go too fast and fail. Stiles has broken into the office to steal Theo's transcripts and finds out that he's father's signatures are different. Still no one thinks he should be raising the alarm. Stiles storms out and Liam seems to be the only one willing to help.
Lydia and Parrish are hitting it off. They're going to work together on figuring out what's going on with Tracy. Stiles and Liam's stalking is finally proving fruitful when Theo wanders into the woods at night. Liam relies that he was meant to meet Mason, Stiles tries to persuade him to tell Mason. Liam worried, misses the trap set and falls in, his phone falls out. When he picks it up he notices a leaf earring in the mud.
Liam and Stiles find out that Theo is really sad and throwing flowers in the river in order to honor his sister who died. Stiles realizes they have to leave but Theo's already noticed them and confronts them. Stiles gives him the little evidence he has and definitely let's Theo know he doesn't trust him. Theo tells them he knows he was meant to be in this pack.
Tracy's father has boarded up the skylight but he has to leave her alone in the house. He promises that nothing will happen to her, which obviously means something is about to happen to her. Back in the woods, Scott catches up with Stiles and Liam. Embarrassed, Stiles tries to leave but his jeep won't turn on. Him and Scott start to talk about why Stiles doesn't trust anyone, he responds that Scott trusts everyone.. Stiles gets mad and punches his car. Scott heals his hand.
Parrish is keeping an eye on Tracy's house but it's too late. Tracy is standing in the middle of the street behind his car. Liam finally makes it back to the school. He's about to Mason but a black wolf appears in the parking lot behind them. It starts to chase them into the school until Liam growls at it. Mason finally knows and he doesn't seem a bit scared at all. In fact he seems to think it's pretty cool. Turns out the wolf is not Derek but Theo.
Kira and Scott are making out but she stops to ask him why he didn't tell her about UC Davis. Scott tells her that it's because he doesn't believe he's smart enough. Lydia and Parrish enjoy a coffee and a pat on the back that Tracy's all safe. Even though she's not, she's in the doctor's place. They shoot her with something. Turns out all the night terrors were just her as a werewolf.
Stiles is back at his theory board. His dad tells him that he can't think someone's guilty based on gut feelings. He needs proof first. Stiles points out that the different thing is that his father isn't wearing his wedding band. Sheriff reminds Stiles that a guilty party will always do something wrong. Back at Theo's house, he's interrogating his "parents." They aren't his real parents and Stiles evidence was real.