Deputy Tara Graeme enters the Beacon Hills High School. The hallways are dark, but she hears a door close in the distance. She has her hand on her gun as she walks down the steps toward the boys locker room. Suddenly a group of students cross the hall behind her, and she turns to ask them what they're doing there so late. "Practice for a recital tomorrow," Danny tells her. He asks her if something's wrong and then notices her hand on her gun. "There is something wrong, isn't there." Tara informs them that someone made a 911 call and they all need to leave. The students hurry out.

 

Tara calls dispatch, but no one answers her call. Instead she hears weird chanting coming over the radio. The chanting stops when she lets the radio go. There's a bang behind her, and Tara turns around with her gun drawn. She sees legs being dragged into the boys locker room and goes to investigate. She announces herself, and orders whoever is in the locker room to step out with their hands in the air. 

 

She heads back into the showers and sees herself lying dead up against the wall. The Darach appears behind her with a garrote and starts to strangle her. Tara drops her gun and quickly falls dead just where she saw herelf a moment earlier.

 

Scott and Stiles arrive at the school. Stiles asks where "she" is, and Allison answers, "Over here." Lydia explains that it was the same thing as what happened with the pool. "I got in the car heading somewhere totally different and ended up here. And, you told me to call you if there's a dead body." Stiles is surprised because she didn't mention there was a body, but Lydia replies that she hasn't found it yet. "Not yet? What do you mean not yet?" She informs him that she's not finding dead bodies anymore. She's happy to leave that work up to Stiles. "How are we supposed to find the dead body? You're always the one finding the dead body."

 

But Scott has already seen something. "Guys, I found the dead body," he says. Tara is lying on top of the Beacon Hills High School sign. 

 

The following morning, Stiles watches as his father talks with some other officials. The Sheriff catches him watching and comes to talk to him. The Sheriff is aware that Stiles thinks people are dying in threes. "Dad, murdered, okay? Sacrificed, actually." The Sheriff tells him that half the state and the FBI are coming in on the murder cases and they're not going to accept a cop being killed. Stiles is upset that it was Tara, who helped him with his math homework.  His dad tells him to get to class. 

 

Allison is at home, still under the covers. Her dad asks her about the recital to honor all the people who have been killed. He asks if she'd like him to take her to the event. Allison says she isn't feeling up for it, but she's just playing him. As he leaves, Chris tells her to take as many days as she needs. School can wait. It is unclear why Allison is at home. 

 

As soon as Chris closes the door, Allison whips off her covers to reveal that she's fully clothed. She gets ring daggers out of a case in her closet. She on her way out the door when she hears a sound out the window behind her. She turns, dropping her coat, and throws the window open. She drags Isaac inside, throwing him to the floor, and holds the dagger to his throat. "What do you think you're doing?" "You weren't at school." She asks if Scott sent him to check up on her, and Isaac explains that maybe Scott's worried her. "I can take care of myself." "Yeah, I've noticed. More than once." They smile a little at each other.

 

At school, Ms. Blake talks about images, analogies, metaphors, and similes. She stops at Lydia's desk because she sees her drawing a tree and comments that she didn't know she had so many hidden talents. "You and every guy I've ever dated," Lydia replies. Ms. Blake tells her that she just used an idiom. "Idioms are something a secret to the people who know the language or the culture. They are phrases that only make sense if you know key words. Saying 'jump the gun' is only meaningful if you know about the starting gun in a race." She looks at both Scott and Stiles nervously and then brings up the phrase "seeing the whole board," which Stiles knows refers to chess because his dad plays.

 

As Ms. Blake moves away, Scott tells Stiles that he thinks he can get to Ethan and make him talk. Stiles wonders why Scott would want to do that. "The Druid are emissaries, right? So what if the Darach was an emissary to the alphas?" Stiles complains that such sentences even make sense to him. He further points out that the problem with getting to Ethan is going through Aiden. 

 

Out in the hallway, Aiden tells Ethan that he needs to stop seeing Danny. "He's harmless," Ethan replies. He points out that Lydia is the one they're supposed to worry about. Aiden demands to know why Ethan is still talking to Danny, and Ethan evades the question. "What do you think we're doing here? You know we're not actual high school students, right? We're here to eliminate a threat." Ethan defends himself by saying that since Danny is harmless, the threat is eliminated. Aiden smiles because he realizes that Ethan's starting to actually like Danny. He asks if Ethan would kill Danny if Deucalion ordered him to. "If Deucalion asks you, would you kill me?" Ethan replies. Aiden repeats his order for Ethan to stop seeing Danny or he'll rip the flesh off his face and eat it.

 

Stiles says that ever since the twins have been back at school they've been together all the time. "How are we going to separate them again?" Both he and Scott have an idea, and they turn and look at Lydia. 

 

Lydia gets Aiden into the Coach's office and starts kissing him, but he's not immediately into it. He says he's surprised since she's barely talked to him since he killed Boyd. "I told you that was Kali. I didn't have a choice." Lydia tells him that she thought they were all alphas. "Yeah? Well it's not as democratic as it sounds." He further claims to not feel remorse because Derek killed Ennis. Apparently no one is aware that Ennis would have lived if Deucalion didn't crush his skull. Aiden then informs Lydia that there was a time that Derek and Boyd tried to kill her. Lydia stares at him. "How did you know about that?"

 

Before Aiden can answer, someone scratches a revenge spiral on the frosted glass on the door. Aiden takes it a threat from Derek.

 

Stiles and Scott catch Ethan alone in the hallway. "Why are you even talking to me? I helped kill your friend, how do you know I'm not gonna help kill another one?" Ethan asks. Stiles takes it as a threat. "You know what I'm gonna do? I'm gonna break off an extra large branch of mountain ash, wrap it in wolfsbane, roll it in mistletoe, and shove it up you freaking--" Scott calls Stiles off and explains that they're talking to him because he doesn't think Ethan wanted to kill Boyd and if he had to do it over again, wouldn't do it. "You know what we owe them. Especially Deucalion. We weren't like Kali and Ennis when we met him. We weren't alphas." Ethan admits that they were omegas at the time.

 

The lore about omegas as explained by Ethan differs from what has previously been described. He explains that they were part of a wolf pack, not loners, but were on the bottom rung and treated poorly.

 

Meanwhile, Aiden opens the door to the office and calls Derek out. Lydia threatens to scream. "You wanna fight, Derek, come and get me!" Aiden says. Cora attacks him from the side. 

 

Ethan explains to Scott that the pack they were part of were killers who gave Werewolf the reputation for being monsters. Their alpha was the worst. "Why didn't you guys just fight back. Form Voltron Wolf, you know? Kick everyone's asses." They couldn't because they didn't know how. Deucalion taught them how to meld together, and they killed their old pack. Their alpha begged for his life, but they tore him apart. Scott asks about their emissary, and the look on Ethan's face tells him that they killed him too. He confirms that all the emissaries are dead except for Deucalion's. 

 

Ethan suddenly gasps and touches his chest in pain. He says that it isn't him but Aiden who's in trouble. 

 

Aiden roars at Cora and grabs her by the throat. He throws her across the locker room, and then picks up a weight from the bench press. Lydia begs him to stop, but he beats Cora on the head with the weight. He's about to hit her again, but Scott and Ethan stop him. "Aiden! You can't do this!" "She came at me!" "It doesn't matter! Kali gave Derek until the next full moon. You can't touch him or her." Aiden looks at Lydia, and he stops resisting. Ethan nods at Scott and takes his  brother away. Stiles thinks Cora's hurt worse than she looks.

 

At the Argents' apartment, Allison has explained to Isaac about the map. Isaac asks if she think her dad is the killer. She doesn't. She hopes he isn't. She shows him that there are 5 more bodies to be found, but it doesn't say who the bodies are. Isaac steps back from the desk. When Allison asks what he's doing, he says that it's something he learned from his father. "Take a step back. Look at the whole picture. Sometimes you see things you wouldn't notice if you were up close when all you're looking at are the details.

 

Allison steps back from the map and bumps into Isaac. "Look at that, you see that?" she says. She moves the map and reveals a five-fold knot on the top of the desk. Isaac grabs her hand and moves the blacklight she's holding over the knot. It reveals: virgins, warriors, healers, philosophers, guardians. 

 

Cora cleans out her wound while Scott, Stiles, and Lydia watch. She tells them all that she'll heal and tries to stand up straight, but she wobbles and Scott catches her. "Do you realize how suicidally crazy that was?" Stiles asks her. Cora replies that she did it for Boyd because none of them were doing anything. "We're trying," Scott tells her. "And you're failing. You're just a bunch of stupid teenagers, running around thinking that you can stop people from getting killed. But all you do is show up late. All you really do is find the bodies." 

 

She walks away from them. Stiles comments that she's definitely a Hale and then volunteers to make sure she gets home. 

 

Outside the school, Jennifer runs down some steps and finds Derek walking out into a parking lot. She rushes toward him and jumps into his arms. They kiss. "Where the hell have you been?" she asks. "And don't say that you needed to be alone for a while because that is the single worst excuse ever."  He doesn't say anything, and she realizes that that was going to be his excuse. "Oh God, I'm sorry. You really did need to be alone, didn't you?" He tells her that he's there now and that she's safe. She explains that she doesn't feel safe because the twins are walking around school like nothing happened. He assures her that the twins aren't going to hurt her.

 

The bell rings signaling next period, and Jennifer complains that some days she just wants to take a sledgehammer to the bell. Derek grins and asks her to come back to his loft with him. She says that she can't because she has three more classes and she organized a recital honor the losses at the school. She thinks maybe it sounds a little dumb, and Derek tells her that it sounds perfect. They kiss again, and then she heads back to class.

 

Scott goes to Ms. Morrell's office and tells her that he could use a little guidance right now. 

 

"Philosophers?" Stiles asks. Allison called him to tell him about what they found. She also tells him Guardians was on the list, which she thinks must be law enforcement. Stiles is driving Cora home. "Stiles, you have to tell you dad," Allison says. "Tell him whatever you need, but you have to get him to believe." Stiles agrees and tells Cora that he's going to need her help.

 

Morrell asks Scott why he's bothering with her when he knows someone else is about to be taken. Scott asks her if she's the one killing people. She tells him to listen to her heartbeat and then whispers, "No. I'm not the one killing people." Scott seems satisified that she isn't lying. "The truth is I'm all that stands between Deucalion and the lives of your friends. I've been the one pulling the leash taut when they're salivating for a bite." Deucalion wants a True Alpha in his pack, and he thinks Scott will be that Alpha. Scott demands to know what Deucalion wants. "He wants to make a killer out of you. That's what he does." "But if I kill someone, I can't be a True Alpha, right?" Morrell confirms this. She explains that Deucalion is an obsessive. He both wants Scott and fears him, and if he can't have Scott he will destroy him instead. Either Scott willingly becomes part of his pack, or he'll make Scott into a killer, destroying his potential to be a True Alpha. Scott is adamant that neither of those things will happen. 

 

The problem is that Scott is playing Deucalion's game. So while they're still trying to figure out what's going on, Deucalion is ten moves ahead. 

 

The history teacher, Mr. Westover, just finished writing his notes for WWI on the board. He turns around for a second to check something, and when he turns back, all his writing has been replaced with a five-fold knot. He drops a piece of chalk, and the chalk rolls along the floor into Lydia's foot. She picks it up and walks into the classroom. She writes a number 2 in one of the circles, and then lets loose with a scream.

 

Lydia asks Ms. Blake why no one is calling the police. Jennifer tells her that they're going to make an announcement over the PA system, but Lydia insists that Mr. Westover has been taken like the others and will be the second murder. Ms. Blake point out that Lydia wrote the number 2 on the board. "Okay, fine. I'm psychic," Lydia says. When no one believes her, she shouts, "I'm something!"

 

Ethan asks Scott what a deputy and a teacher have in common, but Scott doesn't know what the pattern is. 

 

Stiles is in his room with his father and Cora. He paces back and forth, unable to figure out how to start talking. His father tells him that he doesn't have time to waste. Stiles starts by pointing out that for the last year he's had all these cases that he couldn't figure out. All the murders surrounding Kate Argent and then Matt killing all the people who had drowned him and now all the new murders, it's like he's been playing a losing game. "Stiles, the last thing I need right now is a job performance review from my own son." "That's just it, Dad. The reason that you're losing the game is because you've never been able to see the whole board," Stiles says as he grabs a chess set. "I need to show you the whole board."

 

Allison has a text from Scott telling her that Mr. Westover is missing. "I have to stop him," she says. She's convinced now that her father is the killer. He knows everything and has everything mapped out. Allison pulls out her map of the telluric currents. If Mr. Westover was taken from the school, then there must be a corresponding point on the telluric current where he will be sacrificed. They find a new circle on the map and decide that that's where they need to go.

 

Back in Stiles's room, the Sheriff repeats that Scott and Derek and werewolf. Kate Argent was a werewolf hunter. "Along with Allison and her father," Cora adds. "And my friend Deaton, the veterinarian, is a kanima?" "No no no, he's a Druid." The Sheriff asks who the Darach is, and Cora replies that they don't know yet. The Sheriff sighs and sits back. He asks why Jackson was the kanima. "Because sometimes the shape that you take reflects the person that you are," Stiles replies. 

 

Angry, the Sheriff gets up to leave, but Stiles stops him. He points to Cora and says that she's one of them. Stiles gets him to stop before leaving and asks Cora if she's ready. Cora gets up to shift but passes out instead. The Sheriff pushes past Stiles to check on her and tells Stiles to call an ambulance.

 

Isaac and Allison find the place where they think her father has Mr. Westover. "Really don't think we should call Scott?" Isaac asks. Allison tells Isaac to stay behind her and stay quiet. "Ooh, this is so not gonna end well," he says before he gets out of the car to follow her.

 

They walk into a large, empty building. "FYI, if your dad tries to kill me, I'm gonna defend myself," Isaac says. "If my dad tries to kill you, you'll be dead," Allison replies. Isaac stops suddenly because he smells blood. She asks what direction it's coming from, but he tells her he's not that good at being a Werewolf yet. He thinks it's coming from straight ahead. Allison starts to head that direction over Isaac's objection. They can see Mr. Westover and the Darach. Isaac tackles Allison as Chris comes out of nowhere and starts shooting at the Darach. 

 

Chris emtpies his clips and slides in fresh ones. He orders Allison and Isaac to cut Mr. Westover down. Allison realizes that they were wrong about these sacrifices being Guardians as in law enforcement.

 

Scott tells Stiles that it's Philosophers, as in teachers. Tara used to teach middle school before she was a cop. Stiles is at the hospital. He tells Scott that there are dozens of teachers who are all headed home, so it will be difficult to tell who to protect. Scott turns around and realizes that all the teachers will be at that evening's recital.

 

Ms. Blake stands outside, greeting people as they arrive for the concert. She hugs herself as a cold wind blows. 

 

Allison confirms that her father was tracking the killer on his own the whole time. "And I was this close," he says as he polices his brass. "Could've caught him if the two of you--" Allison is incredulous that this could be her fault since he's the one who's been lying for the last 2 months. Chris doesn't think she's been very truthful either. Isaac suggests they have a family spat later because there's still one more teacher that's going to die.

 

Stiles follows his father down the hall of the hospital asking him what he saw happen to Scott when he tried to save Deaton. He saw Scott healing himself after he tried to cross the mountain ash.  "I don't know what I saw." "You saw something that you can't explain." The Sheriff turns on him and tells him that he's seen a lot of things that he can't explain, that doesn't make them supernatural and it doesn't make them real. "They just found another body. That's real. And that's the lead I'm following." Stiles tries again to tell his dad that another teacher is going to die if he doesn't listen to him. "I am listening! I have been listening!" the Sheriff shouts at him loud enough that everyone stares. Stiles realizes that his father is hearing him, he just doesn't believe. As the Sheriff walks away, Stiles says, "Mom would've believed me." It's a low blow. 

 

At the school, everyone gets ready for the concert. "I know how to tie my own tie," Danny says to Ethan. "You know how to do it badly," Ethan replies. He straightens the tie for him. He also fusses over Danny's hair and puts a mint in his mouth. Ethan asks if Danny's still nervous, and Danny says that he's all good. Ethan's about to let him go but turns back. "Listen, if anything happens, find me. Okay? Find me first." Danny frowns at him a little  but nods. When Ethan turns, Aiden is watching him.

 

Scott notices the twins in the auditorium. Lydia comes up next to him. He thought she was going home, but she tells him that she can't. She doesn't know why she keeps finding the bodies, but maybe if she stops trying to fight it, she could find them before they die. Scott swears that if she can figure it out with enough time to for him to do something about it, he will save people.

 

Derek is at the hospital holding Cora's hand. She comes around and says his name. "'What's happening to me?" "I don't know. But I'm not leaving, okay? Not again." He kisses her forehead. 

 

The Sheriff asks Melissa for files that are over 10 years old. She tells him that he'd need a court order unless he had someone like her willing to bend the rules for a handsome face.  (NOTE: The file cannot be over 10 years old. The Darach was made after Deucalion was blinded and Derek killed Paige, which was 7 years ago. The Sheriff must be misremembering how long ago it was.)

 

The Argents arrive at the school. Allison and Isaac run into the auditorium. Chris looks around at the baleful wind outside. 

 

At 7:00 the students begin to play. Lydia gets a text from Aiden. She looks for him in the crowd, and he turns around to nod at her. "Life or death!" his text says. As she leaves, Chris, Isaac, and Allison walk in and nod to Scott. 

 

Melissa gives the Sheriff a file that matches what he described: slash marks all over the body, the doctors thought it was an animal attack. She tells him that something else happened at that time that was even stranger.

 

In the audience, Aiden searches around looking for his phone. He can't find it. 

 

Melissa says that while the patient was struggling to live, hundreds of birds kept flying into the walls and windows. She says it was like they were committing suicide. "Or sacrificing themselves." "For what?" "Not what, who."

 

Lydia heads into a different part of the school. She's alone in a classroom, when she starts to hear the evil chanting from the concert. Ms. Blake steps out of the shadows and hits Lydia before she can scream. 

 

Scott and Stiles run out of the auditorium calling for Lydia. Scott looks around with his wolf vision, but he can't see anything. Stiles notes that Lydia isn't answering texts. He asks Scott what they should do, but Scott doesn't have an answer. 

 

The music at the concert gets more sinister, and the people in the audience start to notice. Ethan and Aiden look concrned. 

 

Lydia wakes up and asks Ms. Blake what she's doing. "What's necessary. I'm still surprised none of you seem to get that. You call them sacrifices, but you're not understanding the word." Ms. Blake says they're a necessary evil. Lydia asks her to stop but she can't because she knows how dangerous the alpha pack is. 

 

Lydia isn't going to be a sacrifice, though. She's just a girl who knows too much. Ms. Blake tries to strangle her, but Lydia gets a hand between her throat and the garrote, and then she screams. The werewolves at the school all hold their ears in pain. Even Derek at the hospital can hear her. 

 

Ms. Blake is stunned. "Unbelievable. You have no idea what you are, do you? The wailing woman. A banshee right before my eyes." Lydia is crying and shaking. Ms. Blake tells her she looks like an innocent flower but is the serpent under it. She tightens the garrote around Lydia's neck and holds a knife next to her throat, waiting for the last philosopher to die. 

 

The musicians pound away at their instruments, playing like they are possessed. The pianist strikes the right note, and the piano string snaps. It slices her neck open. People scream and start running. Allison runs up toward the stage. 

 

Ms. Blake is about to kill Lydia when the Sheriff tells her to drop it. He has his gun pointed at her. Jennifer throws the knife at him, hitting him in the right chest. He drops his gun. Scott appears, fully shifted, and attacks Ms. Blake. She dodges his swipe and sends him flying across the room with one hit to his chest. Scott spits up blood. 

 

Stiles shows up, and Ms. Blake shoves her desk toward the door, blocking his way. 

 

The Sheriff picks up his gun again. "There was a girl years ago. I found her in the woods. Her face and body slashed apart. That was you, wasn't it?" "Maybe I should have started with philosophers, with knowledge and strategy," she replies. He shoots her in the leg, but it heals back. "Healers," she says. She grabs the knife embedded in his chest, making his drop his gun, and backs him up against the wall. "Warriors." She rips the badge off his chest and crushes it. "Guardians." And then looks at his mouth. "Virgins." And then kisses him. After she does, the Sheriff opens his eyes and sees the Darach without her glamor. 

 

This recitation is believed by many fans to show what powers Ms. Blake gained from each set of sacrifices, although it remains unclear what particular power the Virgins sacrifice gained her, since it is not powering the glamor that makes her beautiful. 

 

Stiles struggles his way into the room as Scott regains consciousness. Windows shatter, and the Darach and the Sheriff are gone.