Somewhere in the Preserve, a young couple are living in a trailer. The wife is angry that this is what they have been reduced to, and her husband, Sean, insists that just because they're living in a trailer doesn't make them trailer park trash. They argue more, and the power in the trailer goes out. The man goes to look at the generator, exasperated. His wife starts to cry from feeling slightly terrified all the time, and he hugs her. Sean goes outside, and his wife hears something that worries her. Sean is outside arguing with someone. The hooded man points up toward a tree, and the kanima's tail suddenly snakes down and grabs Sean by the neck. The hooded man points toward the trailer, and the wife hurries to lock all possible ways in. Sean is thrown through the trailer window, dead. His wife screams. And then his body is dragged back out. The kanima starts coming through the window. It hisses at her and looks at her pregnant belly, but ultimately lets her live.
Scott and Stiles talk to Allison on speaker phone. Allison tells them that Jackson may not know he's being controlled. Stiles suggests that it could be a fugue state like when Lydia left the hospital. Jackson would forget about the murders and getting rid of the blood. And we see Jackson showering blood from his body. They all agree that someone had to manipulate the video, and that must be who's controlling him. Stiles confirms that Jackson thinks he's becoming a Werewolf and that Lydia somehow affected his transformation. They decide to try to convince Jackson that he's not becoming a Werewolf because they think it will help them find out who's controlling him.
The Sheriff pulls Scott and Stiles into an interrogation room and reads out the restrictions of the restraining order Jackson's father has taken out against them. They cannot go within 50 feet of Jackson, speak to him, approach him, or assault him physically or psychologically. Melissa McCall and David Whittemore are in the room witnessing. The Sheriff drops the order to the table, and Stiles asks him what about school. They can attend classes while attempting to maintain a 50 foot distance. Stiles asks what happens if they both have to use the bathroom and there are only two stalls and they're right next to each other, and the Sheriff glares at him while David Whittemore gets incensed at Stiles making a joke. The Sheriff takes Stiles out into the hallway and reminds him that he's lucky Jackson isn't pressing charges. Stiles explains that it was all a joke and he didn't think it would be taken that seriously. The Sheriff asks him how he's supposed to interpret the humor of a stolen prison transport van. Stiles exclaims that they filled the tank.
Melissa leads Scott out and stops to tell him that she didn't think a restraining order was a low that he'd reach quite this soon. She counts off his bizarre behavior and the late nights coming home and having to beg Mr. Harris to let him make up a Chemistry test, and then tells him that he's grounded. He gets no TV (which is already broken) and no Stiles. Stiles starts to protest, but Melissa yells, and he backs off. She also takes Scott's car keys. She fumbles with trying to remove the key from the keyring and Scott eventually just puts his hands on hers to make her calm down. She asks him what's going on with him and whether it's about Allison. Scott sighs and asks her if she really wants to know. Stiles is in the background shaking his head a thousand times no. Melissa asks if it's about Scott's dad, and Stiles nods. Melissa decides it must be that and they'll talk about it at home. Scott declares himself the worst son ever, and Stiles says he isn't winning any prizes either. They watch as David Whittemore yells at Sheriff Stilinski for the way Stiles was mocking him earlier.
In the subway station, Isaac asks Derek why they need Scott and Stiles's help. "Because it's harder to kill than I thought, and I still don't know who it is." He thinks Scott and Stiles might, so he needs Erica or Isaac to start a friendship with one of them. Erica muses over which one. Derek doesn't care. Isaac points out that the full moon is coming. Derek is aware and opens up a trunk full of restraints. He pulls out chains and straps. Isaac says they were supposed to be learning to change whenever they wanted. Derek tells him that there hasn't been time. "But if you have to lock us up on the full moon, that means--that means you're alone against the Argents," Isaac says. Derek points out that they haven't found them, but Isaac thinks it's only a matter of time. He suggests forgetting about the kanima. "We can't! There was something about the way Gerard looked at it. He wasn't afraid. At all." He doesn't know what that means other than that they have to get to it first.
Allison meets Scott and Stiles in the library. They talk between the bookshelves to avoid the cameras. Allison hands Scott a tablet with the bestiary and Lydia's translation. Lydia was very confused as to why this was a top priority task. Allison told Lydia that they were part of an online gaming community that battles mythical creatures. Stiles says that he is part of an online community that battles mythical creatures. The translation doesn't tell them how to defeat it, but it says that Stiles was right about the kanima being a weapon of vengeance against murderers. There's a story about a South America priest who used the kanima to execute murderers in his village until the bond grew strong enough that the kanima would kill whoever the priest wanted it to. Allison says that the kanima is supposed to be a Werewolf but it can't be "until it resolves that in its past which manifests it." Stiles comments that if it means Jackson could use a few thousand hours of therapy that isn't exactly news. Allison suggests that it could have something to do with his real parents. Stiles suggests that Lydia might know. Allison says she'll talk to him to see if he knows anything about them. Scott asks what he should do, and Allison tells him to take his make-up Chemistry exam. They hold hands, and she asks him to promise to take the test. Scott asks her to run if Jackson tries to pull anything, but she insists that she can take care of herself. Scott tells her that if she gets hurt while he's taking a test, someone's going to have to take care of him. Stiles shoves his head through the shelf and tells her that if Jackson does anything evil she should run. She shoves his face away.
Jackson comes into the Biology lab and checks out the tarantula and snake. He's particularly interested in the snake and picks it up. It slithers around his arm and neck and into his open mouth. The Biology teacher comes in and asks Jackson if he still wants to discuss his paper. Jackson doesn't reply.
12 noon, and Scott is taking his Chemistry exam. Melissa goes into Scott's room and starts cleaning up. She argues with herself over whether she's going to snoop around his room. She decides to "straighten up" and puts his guitar back against the wall. She checks his chair, his books, and his closet. Then under his mattress and digs through his clothes hamper. She checks his desk drawers, and then while sitting at his desk sees a box of condoms. There's only one left from a box of 12. She looks distraught. Scott is a half hour into his test.
Jackson heads to the boys locker room. He hears Allison trailing him but doesn't see her. She goes to follow him in and runs into Matt. She startles him and doesn't have a good explanation as to why she's lurking around the locker room door. He notices that she's carrying her high heels, and she claims that her feet were hurting. "Same reason I never wear mine," he replies. She doesn't really hear the joke. He asks her if she knows there's a rave happening and offers to get tickets if she'd like to go with him. The rave is Friday. Matt says he's looking forward to it. Allison barely seems aware that she just agreed to go on a date. As Matt leaves, Allison hears Jackson gasping in pain.
Stiles asks Lydia about Jackson's parents. She claims she's not supposed to tell anyone, but he says that anyone who says that is actually dying to tell someone, so she should just spill. She asks who he's going to tell, and he claims no one, so she won't tell him. Erica appears, eyeing up Stiles.
Allison goes into the locker room and calls Jackson's name. He calls out to her, and she finds him naked under the shower. She turns away and says he could have warned her. "You're the one that walked into the boys locker room," he says. She decides that she can talk to him later, but he stops her from moving and says they can talk now.
Stiles is still trying to get Lydia to talk when Erica slams him against the wall and demands to know why he's asking those questions. "Why are you bringing out the claws on camera?" he replies. She puts them away. Stiles says that if she wants to play Catwoman, he'll be her Batman. Erica tells him that if he wants to know about Jackson's real parents they're a half mile away in Beacon Hills Cemetery.
Allison tries to get away claiming that she has class, but Jackson tells her that she can skip one class. He asks her if she's okay because her heart is beating like crazy.
Scott's test hour is up. He's not done with his test, but he can hear Allison's heart beating from across the school.
Stiles chases after Erica and asks her if she knows how Jackson's parents died. "Maybe. If you tell me why you're so interested." Stiles doesn't say anything, but Erica realizes that Jackson must be the kanima.
Scott hands in his unfinished test, but Mr. Harris tells him that he's not leaving until every bubble is filled in. Scott angrily fills in B for every remaining answer.
Jackson keeps threatening Allison, and she gets more and more flustered. She says she changed her mind about wanting to talk. He doesn't believe her and asks if she's stressed over her relationship with Scott. "I still can't believe that you think your little Romeo and Juliet story is gonna last. You know he's eventually just gonna run to Derek and join up with him and his little wolf pack, If you don't realize that, then you gotta be the stupidest bitch in this town. Other than Scott, since he's a pretty stupid bitch himself." Allison begs him to stop. Jackson gets angrier and cages her in, demanding to know who she thinks they wolves are going to kill next. He tells her that if she thinks being in love is going to save her then she's already dead. Jackson's claws come out, and he draws them along her face. "I just hope your dad's been teaching you moves to protect yourself." "Actually, he has." She grabs his wrist and tries to throw him. Then end up on the floor with Jackson on top. His demeanor changes suddenly, and he wants to know why she's there and what she's doing in the locker room. Scott comes in, and Allison tells him that she's fine while Jackson hurries to put on some clothes. Scott attacks Jackson and throws him into some lockers. Allison keeps shouting that she's fine. Jackson yells that he has a restraining order. "Trust me, I restrained myself," Scott replies. Jackson attacks Scott back, throwing him into a wall and then hurling him toward the showers. They fight, and Jackson kicks Scott into the wall so hard he breaks the tiles. Jackson throws a 45lb weight at Scott like a Frisbee, and Scott catches it. Jackson kicks him into the wall again and then slams him through a sink.
Stiles tries to explain to Erica that there's a lot more going on that they don't know about. "And just because you got the alpha bite makeover doesn't give you license to go around destroying people." "Why not? That's all anybody ever used to to do me. I used to have the worst crush in the world on you. Yeah, you, Stiles, and you never once even noticed me. Exactly how you're not even noticing me right now." Stiles was actually looking at the water coming out of the locker room, and then Scott comes flying through the door. Erica restrains Jackson, while Stiles holds back Scott. Mr. Harris comes down the hall demanding to know what's going on. Matt is there, and he finds Scott's tablet with the kanima translation. He forwards himself the file. Mr. Harris demands explanations from Scott and Stiles. When he doesn't get anything, he hauls Jackson, Stiles, Scott, Allison, Erica, and Matt in for detention.
Melissa McCall goes to the school to talk with Victoria Argent. Victoria assumes she wants Scott brought to the office, but Melissa tells her that she's there to talk.
Lydia is at her locker talking to Young Peter Hale again. He asks her if she's busy after school. She says she always is, and he tells her to unbusy herself because he wants to show her something. He tells her to bring the flower he gave her.
At 3:00, Mr. Harris directs everyone to their seats in the library. Jackson tells him that he can't be in detention with them because he has a restraining order against them. Mr. Harris asks if it's against all of them, and Stiles says it's just him and Scott. Mr. Harris moves Scott and Stiles one desk further away. Scott is still ready to kill Jackson. "No, your'e not. You're gonna help find out who's controlling him and then you're gonna save him," Stiles explains. "No, you were right, let's kill him." Matt keeps looking at the bestiary page he took from Scott. Allison notices him, mostly because he says "kanima" out loud.
Victoria tells Melissa that she thought their kids were no longer dating. "Me too. But it looks like they are. And more. A lot more." Victoria asks how Melissa knows it's not some other girl were severely low standards. Melissa replies that Allison is the only girl Scott has ever talked about. Melissa says she wants them to be safe. Victoria agrees.
Stiles suggests that maybe the master is Matt, because it all comes back to who edited the video. Scott points out that Matt was the one who discovered the missing video, and Stiles says he's just trying to throw suspicion off himself. "So he makes Jackson Isaac's dad, one of Argent's hunters, and the mechanic working on your Jeep?" "Yes." "Why?" "Because. He's evil." Scott points out that Stiles just doesn't like him, and Stiles concedes that Matt bugs him and he doesn't like his face. Scott asks for additional theories. Jackson starts getting one of his headaches that indicates he's going to change. He gets up to go to the bathroom, much to Mr. Harris's concern. Mr. Harris follows Jackson. As soon as he's gone. Stiles and Scott sit with Erica. Scott asks her how Jackson's parents died. She tells him it was a car accident. Erica's dad was the insurance investigator. Jackson will be getting a huge settlement when he turns 18. Stiles is incredulous that Jackson will become even richer. Erica offers to look up the insurance report in her dad's inbox. Scott gets called to the principal's office. Jackson goes into the bathroom and when he looks in the mirror, the snake he ate earlier bursts out of his eye and goes down the drain.
Lydia is at home searching her bag for the flower Young Peter Hale gave her. She can't find it and goes outside to the spot by the pool where he picked one the first time, but she can't find another one like it. She looks out the back gate and is drawn toward it.
Jackson comes back into the library. Stiles and Erica are reading the report on her laptop. They figure out that Jackson's parents died before he was born and he was delivered from his mother's body at the hospital even though she was DOA. Mr. Harris leaves but tells everyone else they have to stay and reshelve the carts of books.
Scott goes into the principal's office to find Victoria angrily sharpening a pencil. She tells him that she's concerned how Allison ended up mixed up in detention with Scott and Stiles. "A sink was ripped off the wall. You're lucky I'm here to explain that to people somehow. You realize that?" Scott says that he does now. Victoria then asks him if he's having sex with Allison and shoves the pencil into the sharpener again. She sharpens the pencil down to a nub, and Scott says that he isn't.
Lydia is walking barefoot through the woods. She comes upon a giant house and goes inside.
Mr. Harris gets in his car to leave. As the car pulls away, we see the same bumper sticker with a quote from Einstein as we did on the car of the kanima's master.
Stiles explains the circumstance of Jackson's birth to Allison and Scott. "They had to pull him out of her dead body." Matt notices Jackson still not looking very good and asks him if he's okay. Allison asks if Jackson's parents' accident was really an accident. Stiles says the report is inconclusive. If they were murdered, it would fall in line with the kanima myth. Allison wonders if it's Jackson or the person controlling him who would be motivated by revenge for a murder. Jackson picks up a book and the spine has his name on it. He blinks, and the hallucination goes away. The next book says Close Your Eyes Jackson. Close Them Now. Scott decides they have to tell Jackson what they learned over Allison's objections. Scott finds the book Jackson was holding on the floor and Matt paralyzed with a cut on the back of his neck. The kanima leaps from bookshelf to bookshelf, destroying the ceiling and overhead lights. Scott starts to shift and calls out to Erica. Stiles and Allison try to shield each other from falling books and debris. Jackson takes down Erica and then appears behind Scott. He's in a half-transformed state. He throws Scott, and Scott scrambles to shield Allison and Stiles. Jackson stands by a blackboard and starts writing. STAY OUT OF MY WAY OR I'LL KILL ALL OF YOU. He then leaps out a window and escapes. Stiles goes to Erica and discovers that she's having a seizure. Allison checks on Matt and determines that he's alive. Stiles says they need to get Erica to a hospital. Erica insists that they take her to Derek instead. Allison tells Scott to go. Scott wants to stay with her, but she says she can call an ambulance for Matt but Stiles can't take care of Erica on his own. She insists that he go. He kisses her forehead and helps Stiles and Erica.
Lydia walks around the empty house calling for people. Young Peter Hale walks up behind her. She asks if this is his house, and he says that it was. However, the exterior of the house previously shown does not match the Hale House. He asks her if she brought the flower. She says she couldn't find it. He tells her that it's okay, but since she doesn't have it he wants to collect his kiss. They start making out. When Lydia pulls away, she sees their reflection in a mirrored wardrobe in the middle of the room. She's holding Peter Hale's burned body, and suddenly the background changes to the interior of the Hale House. She backs away from him in fear, and he asks if something is wrong. Lydia screams, and we see the actual exterior of the Hale House.
Derek brings Erica into the subway car, followed by Scott and Stiles. Derek tells them to hold her up, and Stiles moves so they can lean Erica against him. Stiles asks if she's dying. "She might. Which is why this is gonna hurt." He takes Erica's wrist and breaks her arm. Stiles is horrified. Derek tells him that it will trigger the healing process. He claims he still has to get the venom out of her system and starts squeezing her arm, where presumably her shattered bones have broken through her skin causing her to bleed. She leans back against Stiles and tells him he makes a good Batman. Derek and Scott come out of the subway car, and Scott confirms that Derek knows Jackson is the kanima. He tells Derek he's going to help him stop Jackson as part of his pack. Derek is surprised but doesn't say anything. "If you want me in, fine, but I do it on one condition. We're gonna catch him, not kill him." "And?" "And we do it my way."
At the hospital, Melissa has just helped deliver the baby from the woman in the trailer. The woman tells her that the police don't know about the thing that killed Sean. She falls asleep, and Melissa leaves. As soon as she's gone, the hooded man from the woods comes into the room. He suffocates her.
Back at the Hale House, burned Peter sits down next to Lydia. He apologizes for how confusing everything must be. He thinks she'll pull through this ordeal with a minimal amount of PTSD and a few years of profoundly disturbing nightmares. He tells her that he had a plan and starts playing with her hair. "It was a good plan. But if there's one thing I've learned in life it's to always have a back-up." Her immunity means that she wouldn't turn and she wouldn't die, but she'd be able to do a very important thing. He nuzzles her hair and then disappears before he tells her what. Lydia has flashbacks to all the times she saw Young Peter Hale and realizes that he wasn't there. She opens her hands and finds a wolfsbane flower. The camera pans down to reveal Peter buried under the floorboards of the house.