A helicopter flies over the hospital the same night Sean was killed and Scott bit Liam. The Sheriff and his deputies photograph the crime scene. Sheriff Stilinski asks Parrish to get everyone off the roof and stall the ME for five minutes because he has an expert he wants to bring in. "You have an expert on teenage cannibals?" Parrish asks. The Sheriff doesn't really answer and just asks for five minutes. Parrish isn't happy about it, but he rounds everyone up. As soon as everyone is off the roof, Derek appears behind the Sheriff looking at Sean's body. He's wearing a dad track jacket sort of thing instead of his usual leather. The Sheriff reels from his sudden appearance and tells Derek to be quick. He tells Derek that Scott said Sean was a wendigo. "Cannibalistic shape-shifters," Derek confirms. But he hasn't heard of any in Beacon Hills for a long time. Derek picks up a scent on the air and turns around to investigate. He asks how many people Scott said were up there. "Just Sean and the axe-murderer, who apparently had no mouth." Derek steps up to the ledge and spots blood. "There was someone else. Someone young. Male." The Sheriff asks if Derek can smell his fear, and Derek says that and his blood.
Scott and Stiles rush into Scott's house heading toward the bathroom. Stiles apparently talked to his father in Scott's place and didn't tell him about Liam. Stiles asks Scott what he did with him. "He's upstairs." They head up, and Scott reveals that he's duct-taped Liam and put him in the bath tub. Stiles is appalled and pulls the shower curtain back closed while Liam whimpers. He and Scott sit down on Scott's bed. "So you bit him." "Yeah." "And you kidnapped him." "Yeah." "And then you brought him here." Scott admits that he panicked, and Stiles asks if they're going to end up burying pieces of his body out in the desert. Liam hears this and whimpers more loudly. Stiles takes the opportunity to remind Scott that this is why he comes up with the plans, because Scott's plans suck. Scott admits that he's right and asks Stiles what they should do. They take Liam out of the bath tub and set him up on a chair, still bound with duct tape. Stiles tells him that if he screams when he takes the tapes off it's going right back on. Stiles prompts Scott to take the tape off Liam's mouth, but Scott doesn't move, so Stiles does it. Stiles starts to explain that Liam's seen a lot of confusing things tonight and more confusing things are going to happen because of the confusing things he's seen. Liam doesn't understand, so Stiles prompts Scott to tell him. "Liam, what happened to you, what I did to you, which I had to do in order to save you, it's gonna change you." Stiles adds, "Unless it kills you," and then immediately regrets it. Liam starts to cry, and they both crouch down and try to make him stop. Scott tells him he's not going to die. Stiles is less firm on that point. Scott decides to untie him. Liam gets up and shuffles around while they apologize long enough to grab hold of the chair he was sitting on. He hits Scott with it, breaking it, and when Stiles starts to ask him what the hell his problem is, he punches Stiles in the face and runs. As he's running, he realizes that his ankle is healed. Scott and Stiles fly out into the hallway and barrel after him. There's a lot of screaming, and they tackle him down the stairs. Scott and Stiles wrestle trying to grab him, but Stiles only ends up grabbing Scott's leg while Liam escapes out the front door. "Your plan sucked, too," Scott says.
In the loft, Peter turns off Derek's alarm system and calls out asking if he's there. He looks through some papers, and a tomahawk suddenly flies through the air and embeds into his chest, through the page he was reading. Peter drops to the floor, and the Mute steps out of the shadows. As he's gasping for breath, Peter again calls Derek's name. The Mute responds, "Don't worry, Peter. Derek is next."
The next morning, Stiles drops a bag of restraints on his bed and holds them up for Malia to inspect. She declares that she hates full moons, and Stiles promises that they will get easier. Malia takes one of the damaged retraints and points out that it isn't going to last much longer. Stiles suggests they make tonight the last night she needs them. He fits it over her wrist like he needs to size it and says they might need them for Liam next. Malia asks if they're sure Liam is going to turn. "We're not even sure he's going to live," Stiles replies. The Sheriff walks in and sees them adjusting the restraints. Stiles takes one look at him and declares that it isn't what he thinks at all. His dad just says he doesn't want to know and walks away. Malia claims to not get the joke.
In Biology class, Kira asks Lydia if she's looking at her math notes on her laptop. "No wonder Malia's failing," she says, as the code streams across the screen. Lydia says that some of it is her notes but the rest might be a code. She, of course, doesn't remember writing it. She thinks she should try to figure out what it means before it tries to kill them. Kira suggests that it could be Enigma Code. Lydia thinks is a variation of the Vigenère Cipher. "Do you know how to crack it?" "With a key." Just then Lydia's mom dangles a set of keys in front of her face. "Remember the rules. No more than six people allowed in the lake house. Stay out of the wine. And if anything gets broken it's getting added to your credit card debt." She also tells her to lock up the basement because there were a lot of scratches on the walls like a pack of wild animals got down there.
New kids Garrett, Violet, and Mason Hewitt get off the school bus. Garrett complains about how he's not watching another movie on a Friday night. Mason Hewitt points out that they're freshmen. They're not going to be hitting clubs until 4am. Violet settles on a movie at Mason Hewitt's at 9. Liam comes running up as Garrett and Violet leave. Mason Hewitt asks him why he wasn't on the bus, and he says he ran to school from home, all 3 miles. Mason Hewitt points out that this must mean his leg is okay, but then he asks about the wound on Liam's arm, where Scott bit him. Liam starts breathing heavily and looking ill. When he glances up, he sees Scott watching him with Derek-level creeper skills. Liam tells Mason Hewitt that he has to get to class and hurries away from Scott. In the hallway, Stiles and Scott corner him, and Scott asks him to listen. Liam waits, and Scott says, "Liam... we're brothers now." Only unlike when Derek said it, Scott doesn't sound like he believes it. Liam gives him a, "What?" And Stiles rolls his eyes. "What are you talking about. We just met and you bit me," Liam says. Scott then tries, "The bite is a gift." And Stiles nearly rolls his eyes out of his head at his disingenuous he sounds. "Scott, stop. Please stop." Stiles tells Liam that they're trying to help him. "By kidnapping me?" "Just to clarify, Scott kidnapped you," Stiles says. "I aided and abetted." Scott tells Liam that something happening to him, something big, but he doesn't say what it is. Liam insists that nothing is happening to him and rips the bandage off his arm. The wound is healed.
During a break at school, the pack meets out by the buses. Malia says that she's not sharing her basement with Liam. Lydia clarifies that it's her basement and her mom noticed how she tore it up last time. Their plan is to use the boathouse for Liam because they can chain him to a support beam. Kira asks how they plan to get Liam to the boathouse if he doesn't trust them. Stiles suggests chloroforming Liam and throwing him in the lake if it keeps him from murdering anyone. Malia, of course, supports this plan. Scott says they're not killing or kidnapping him, so Lydia suggests they lie to him and tell him there's a party and invite him up. They get Kira to agree to be a vixen and be the one to invite Liam. Kira agrees and arranges to be walking down the steps as Liam and Mason Hewitt leave class. Her hair flutters in nonexistent wind. Halfway down the steps, she falters and falls on her face. Liam rushes over to see if she's okay, and she smiles and asks him to a party.
Back at the loft, Derek has extracted the tomahawk from Peter's chest. He says it was laced with wolfsbane and since he doesn't know the species they're going to have to burn it out. Derek flicks open a lighter in front of Peter. "I think I can handle a little fire," Peter tells him. Derek makes a pleased face and then uses the lighter to light a blowtorch. Peter's face drops. "Oh, hell." Derek applies the blowtorch, and Peter screams. After it's done, he falls to the floor in agony, but Derek offers him a hand and pulls him up. Peter tells him that the Mute was after him. "How does a guy with no mouth say anything?" Derek asks. Peter shows him the glove with the keyboard that he somehow has.
That night, Kira drives Liam up to Lydia's lake house. It belonged to her grandmother. Liam is having difficulty with the loud music. He asks her to turn it down, but it was already down, so Kira turns it up a little. Liam gets a text from Mason Hewitt asking where he is and Liam tells him about the party. Scott pulls up to the lake house to find Lydia, Malia, and Stiles waiting. Stiles looks concerned, so Scott immediately says that Kira reported the plan was going fine. That isn't what Stiles wants to talk about. He asked around and found out why Liam was kicked out of his last school. He had a problem with one of his teachers and destroyed the guy's car with a crowbar and carved This Is Your Fault into the side. He has anger issues. In Kira's car, Liam glares at his reflection as the full moon starts to affect him. They get to the lake house and Liam immediately notices that no one is there. Kira tells him that everyone is there but it's a small party. That wasn't Liam's understanding of everyone. Kira lies again claiming that everyone else is late and they're early. She takes Liam's arm and brings him inside. As soon as he walks in the door and sees Stiles and Scott he knows he's been tricked. Kira closes the door and won't let him out. Stiles tells him to think of it like an intervention because he has a problem. "And we're the only ones that can help," Scott adds.
Derek brought the glove to the sheriff station to show Stilinski. The Sheriff says he doesn't understand how this guy can have no mouth. "I mean, how can he eat?" Derek takes a beat."Peter didn't get a chance to ask, He was fighting him off with a tomahawk buried in his chest," Derek sasses. The Sheriff asks who runs around with a tomahawk anyway. Parrish overhears this and says that he carried one for IED removal in Afghanistan. "It's military. And so is that," Parrish adds, pointing to the glove. Derek asks Parrish what the glove is used for, and Parrish says that it's been modified. Derek and the Sheriff exchange a look, and the Sheriff closes his door.
The gang has given Liam the rundown of what they are. Werewolf. Werecoyote. Banshee. Fox? "Kitsune," Kira says. Liam then asks Stiles what he is. "For a little while I was possessed by an evil spirit." "What are you now?" "Better?" Stiles says. Liam sees the restraints and asks if those are for him. Malia admits that they're for her. She flashes her eyes, and Liam asks how she did that. Scott assures him that he'll learn but he needs to get through the full moon first. Liam points out that the moon is already out. Scott asks if he's starting to feel something. "I feel like I'm surrounded by a bunch of psychotic nutjobs." Liam starts shouting and getting angrier and collapses from a loud sound. Outside, cars pull up to the house. Lydia asks who they told. Liam admits that he told Mason Hewitt because Kira said there was a party. Mason Hewitt invited everyone. Liam starts to shift, and his nails scratch the hardwood floors. Lydia orders them to get Liam off the floors before he ruins them. Scott and Kira hurry Liam to the boathouse. Malia starts to shift, and Stiles hurries her into the basement. Lydia asks Stiles what she's supposed to do with the horde gathering outside. "Lydia, who throws the best parties in Beacon Hills?" Stiles asks. "What? Me, obviously," she replies, incensed. "Okay. Then throw a party!" Lydia is not amused but opens the doors anyway.
In the Sheriff's office, the Sheriff and Derek watch while Parrish gets an IP address from the glove. While he's typing, the glove moves on its own. Parrish says the glove got a message and asks if anyone recognizes the name Benefactor. The message says: Money Transferred. Derek asks what that means. "That means this guy's not just a killer. He's an assassin," the Sheriff says.
Scott and Kira struggle to chain Liam down. Scott doesn't shift or seem to use an extra strength. Before Kira can chain Liam's hands, Liam breaks free and knocks Scott back. Liam is about to claw Scott when Kira hits him with a paddle and knocks him out. Meanwhile in the basement, Stiles puts the restraints on Malia. He asks her if it's too tight, but she tells him to tighten it. Malia tells him that he can leave, but Stiles says he isn't going anywhere. "To be honest, I'm probably safer down here than at a party with 50 freshman and a very pissed off Lydia." Upstairs, Demarco rolls a keg of beer into the kitchen. Lydia claims she didn't order a keg, especially not domestic. "Trying to tell me no one here wants to drink?" the guy asks. Lydia looks around and picks up a wine glass off her laptop. The laptop is worth $2k and the bottle of wine Garrett was drinking was $400. Lydia asks Demarco for the bill and wonder what the extra hundred dollars is for. He calls it the "yes, you do look 21 to me" fee. Lydia glances around and sees Mason Hewitt heading upstairs. She tells the guy she'll get him some cash and hurries to catch up to Mason Hewitt. While she's gone, Garrett pays for the keg. Scott and Kira watch Liam now that they've got him chained to a beam. Kira comments on how young he looks. Scott says he's only 15. She asks what they're going to do with him, and Scott says they'll help him. "What if he doesn't want our help?" "He will."
Back in the basement, Malia begs Stiles to leave. He insists that he's not going to leave her. "What if I hurt you?" "You're not going to." She says that she wants to. "I look at your face and I want to slash it. I want to tear at it. I want to feel your bones crack between my hands." Stiles isn't particularly shaken by this and says she's not the first person to tell him something like that. He tells her that he's not leaving her and isn't going to let her hurt anyone. She starts to break through the restraints and says that he's not going to have a choice.
Demarco heads out to his car only to find that his tire is flat. He starts getting angry and holds his head like he's getting a headache. Then we see his hands turn into claws and learn that he's a beta/omega werewolf. To control himself he repeats a buddhist mantra, "Three things cannot be long hidden. The sun, the moon, the truth." He controls his shift and drops to his knees. Violet then appears behind him and strangles him with a garrott. She his a button on the garrott which makes it turn hot, and the cord severs Demarco's head bloodlessly. She takes a picture on her phone as proof and then heads back to the party. She finds Garrett, who says their friend just sent him a text. The Benefactor deposited money in their account.
Mason Hewitt looks for Liam upstairs. Lydia follows him into a very white room and asks what he's doing up there. He says he's looking for Liam, and Lydia claims that missing freshman are low on her priority list. Mason Hewitt points out that he can't be so low if she knows he's a freshman. Lydia grabs two wine glasses and tries to hurry Mason Hewitt out, but she drops the glasses with red wine. Lydia drops to her knees and starts trying to clean the carpet with her shirt. Mason Hewitt assures her that the wine will come out. He asks her if the carpet's valuable. "No. That's the problem. Nothing in here is valuable." She starts to cry and explains to him that they put the house on the market and everything has to be in perfect condition to sell for enough. Mason Hewitt offers to get some club soda and salt and assures her that it will come out. Mason gets up to leave, and when the door closes behind him, all the sounds from downstairs stops. Lydia opens and closes the door to test it and realizes the room is soundproof. There's a lot of empty space and only a few pieces of furniture. She's drawn to the turntable and turns it on. What comes out isn't music, just noise and cut off voices. When she looks up at the blank wall in front of her, faces start to press through the surface.
Meanwhile, Scott and Kira sit out at the boathouse. Scott turns and says he can hear the music from the house. They're playing electronic. Kira says that she wishes they played slow songs at parties because she's better at slow dancing. Scott smiles and asks her to dance. Kira looks at Liam, still chained. "What about him?" "He can dance with me next time," Scott replies. As they dance Kira asks Scott how he's so good at staying in control on a full moon. He explains that he has to make sure his pulse doesn't get too fast. He claims to be indistractible. Kira plays with fire and kisses him to see if she can make him lose control. She manages to make his eyes glow. She also says she heard him growl, but Scott looks over at Liam. "That wasn't me." Liam is awake and shifted. Kira asks if the chains will hold him. Scott says they will, but Liam breaks out easily. He runs at them, then leaps through the window and heads out into the woods.
Malia breaks one of her restraints, and Stiles jumps back out of her reach. He tells her to listen to his voice. "Listen to mine. Run!"
Derek and the Sheriff head into the school. The Sheriff has his gun out, which makes Derek smirk. "You know just because this guy connected to the school's wi-fi doesn't mean he's still here." "True. But I've seen enough in this school to keep a gun in my hand when walking in after dark." The Sheriff shines his flashlight around and spots a pool of blood. Derek claims that doesn't make sense. "I should've caught the scent before we walked in." The Sheriff looks even more worried than before. Derek goes to open the door to the classroom, but the Sheriff stops him. "You nervous makes me nervous." He checks through the small window and then ushers Derek back out of the way. The Sheriff opens the door very slowly, only just pulling a trigger wire tight. Derek crouches down to get a look. It's a claymore mine. Then Derek hears the sound of a tomahawk flying through the air and pulls the Sheriff out of the way.
Stiles tells Malia that he's not going to run because he doesn't think she's going to hurt him. "And I think that maybe you're so afraid of hurting me because of what you did to your family." He tells her that he knows what it's like. He remembers being the nogitsune. "And the worst part is I remember liking it. Because I felt powerful. I felt fearless. And most of all, in control. But when I came through it, I learned something else... Control is overrated." Stiles unlocks the remaining restraint on her wrist. She lunges at him but quickly backs down. She's shifted back into a human. Stiles brushes the hair from her face. "You did it." They hug in relief.
Liam runs through the woods with Scott on his trail. Liam tackles him and shoves Scott up against a tree. He demands to know what Scott did to him. "This is your fault! This is all your fault! This is your fault!" Liam is about to slash Scott when Chris Argent shoots a flash bomb arrow into the tree above them. Liam runs, and Scott spots Chris. "How did you know?" Scott asks as Chris comes to him. "I got your text," Chris replies.
Derek fights the Mute and disarms him. He manages to get the Mute's arms behind his back, and Sheriff Stilinski comes up and points a gun into his face. "You have the right to remain silent," the Sheriff says. Derek rolls his eyes. As he's reading off his Miranda rights, Peter comes into the hallway. He starts running at them. Derek shoves himself and the Sheriff out of the way as Peter attacks. Peter slashes the Mute dead and tears off a piece of flesh, possibly the piece where his mouth should have been. The Sheriff holds his gun on Peter as he gets up and Peter wipes off his hands. As Peter walks away, Derek says, "We've learned a better way." Peter replies, "I'm a creature of habit."
Chris explains to Scott that he's arranged a clearing to the north that will contain Liam. All Scott has to do corral him there. "What are you going to do?" Scott asks. "He's your beta, Scott. The better question is, 'What are you gonna do?'" Scott complains that Liam isn't listening to him, so Chris suggests that Scott start using his own words rather than Derek's. Scott takes off after Liam. He finds him trapped between four sonic emitters. Scott turns them off as he approaches. Liam looks up at him. "What's happening to me?" "The same thing that happened to me," Scott replies.
At the party, Kira looks for Lydia. She finds her staring at the wall in the white room, the record almost completely played through. "What do you hear?" "The key. The key to break the code."
Liam cries that his mom and step-dad can't know what's going on with him. He can't do it to them again. "What do you mean again?" "I got kicked out of school and I deserved it." He's embarrassed by the way they looked at him when they saw what he did to the car. He doesn't want them to see him like this. "Like a monster," Scott finishes for him. Scott stands to the crescendo of heroic music and proclaims that Liam is not a monster, he's a werewolf. "Like me."
In the white room, Lydia brings up her notes on her computer. The keyword to decrypt them is: Allison. The text decrypts into a Deadpool or death pool.