A storm rages over Beacon Hills, and multiple emergency vehicles gather around the ER entrance at the hospital. A branch flies through a hospital window, and Melissa shouts orders as they evacuate. All medications needs to be sealed inside plastic bags and given to the patients to carry in their hands. Staff are to mark doors with a red X when they've evacuated all patients from a room. A doctor runs up to Melissa and asks her why the weather is so crazy. It was supposed to be a mild thunderstorm. She nods and tells him that the power is out in several towns and Hill Valley's under a flood watch. The doctor lives in Hill Valley. Melissa asks him if his patients are clear, and he says yes, except for Cora Hale.
Peter is in Cora's room, wiping her brow. He turns and shout, "Hey, anyone wanna tell me when they're getting my niece out of here?" Melissa walks in, apologizing, and stops dead when she sees Peter. "You're supposed to be dead," she says. "I get that a lot, actually," he replies. Cora jerks away and throws up black ooze.
Jennifer arrives at Derek's loft. She runs in looking for him, and then throws her arms around his neck. She says that something happened at the recital at the school and she needs to tell him before he hears it "from them." Derek asks who. "Scott, Stiles. They're gonna tell you things, things you can't believe. You have to trust me, okay?" He asks what it is and promises that he'll listen to her. She kisses him, but something is wrong in the kiss, and she pulls back. "They're already here, aren't they." Derek glances over her shoulder, and Scott and Stiles walk out. She asks if they told Derek that she was the one taking people. "We told him you're the one killing people," Scott says. Jennifer gives a sarcastic reply, suggesting that she must commit human sacrifices on her lunch hour before getting back to teaching high school English. Stiles has tears in his eyes when he asks her where his dad is. "How should I know?" she answers. Then she turns to look at Derek. "Tell me you don't believe this." Derek glances at Stiles, then asks Jennifer if she knows what happened to Stiles's father. She says no. Scott tells Derek to ask Jennifer why she almost killed Lydia. Jennifer plays dumb about that, too. She tells Derek that Scott and Stiles, for whatever misguided reason, are filling his head with an absurd story. One that they can't prove, she adds. Scott holds up a bottle of mistletoe. It's a poison and a cure, so you can use it and it can be used against you. Jennifer realizes what's in the bottle, but Scott flings the contents out at her in a cloud. She loses her glamor momentarily, but they were all able to see that she's the Darach. She tries to run, but Derek catches her by the throat. She begs him to wait because they need her. "What are you?" he asks. "The only person who can save your sister," she says. She tells Derek to call Peter.
Peter reports that Cora is getting worse. She's in an out of consciousness and vomiting up black blood along with one other alarming substance. Derek guesses that it's mistletoe and then hangs up the phone. He starts squeezing Jennifer's throat harder. Scott asks Derek what he's doing, and Jennifer tells him that Cora's life is in her hands. Derek lifts her off the ground by her throat, but Stiles steps forward and tells him to stop. Jennifer says they'll never find Sheriff Stilinski. Scott asks Derek twice more to stop, and he finally drops Jennifer to the ground. She looks up at them in triumph. "That's right. You need me. All of you." Lightning flashes dramatically behind her.
Derek drives, and Jennifer tells him that she's helping because she wants to, not because she has to. "I could still run and you wouldn't have an easy time stopping me. But I don't want your sister to die." She claims she was only doing what she had to do. "Shut up," he says. Jennifer insists that he need to hear the whole story and know how connected they really are. "Stop talking."
In the Jeep, Stiles tells Scott that he thinks something is still off. Even though they proved to Derek what was going on, Jennifer still had a look like it didn't matter. "You know, like it was all still going according to plan." He asks if Scott saw it too, but Scott doesn't answer. They pull up to the hospital. Scott asks what Stiles is carrying. "Well, you got claws. I got a bat." They all go in, with Derek ushering Jennifer by her arm. Melissa sees them and calls after Scott. "What are you doing here, the hospital's evacuating." Scott tells her they're there for Cora. She incredulous that that takes all of them. "Why does Stiles have my bat?" Scott tells her that she needs to leave, and she gets the message. Melissa tells them that the hospital is supposed to be clear in 30 minutes. There are two ambulances that will be coming back, one is 10 minutes out and one is 20 minutes out. Cora will need to be on one of those ambulances. They'll be picking up in the basement garage.
They all head off. In the elevator, Jennifer gives Derek a look. "You don't have to keep me on a leash, Derek, I'm going to help." She looks over one shoulder to see Scott glowering at her and the other to see Stiles holding the bat threateningly. She resigns herself to the situation and waits for the elevator ride to end. They find the room where Cora used to be. There's a pool of black blood on the floor, but the bed is empty. Scott realizes that the black ooze drops make a trail up the hallway. They hear grunting, and then Peter comes sliding up the hallway on his back. He stops at Derek's feet. "We got a problem," he says, and looks back down the hallway. "Big problem." The alpha twins have formed Voltron and roar. Derek wolfs out, and he and the Melded Wolf run at each other. Derek tries to tackle him, but the big guy slams his elbow into Derek's back and then starts punching him in the face. Scott hurries to help and jumps off a wall to slash at the twins. Stiles sees Cora lying on the ground behind the combatants and pulls Peter to his feet. While the big guy holds Scott against a wall by his throat, Stiles and Peter slip by to help Cora. "Ethan, Aiden, stop! You don't know what you're doing!" Scott says. "All we want is her," they reply. Derek and the alpha twins turn to see Jennifer escaping down the elevator.
Melissa gives more orders about the evacuation. Kali and Deucalion enter the hospital and walk right by her. The elevator dings open, and Jennifer walks into the same hallway as Kali and Duke. Deucalion takes the tip off his cane, revealing a blade, and throws his cane like a javelin at Jennifer. It impales the wall next to her head. 2Kali makes a run for the elevator as Jennifer tries to escape. She catches the doors before they close, but Jennifer summons up some magic and repels her away from the door.
Peter carries Cora over his shoulder as they all run. "Don't stop! Don't stop!" Derek shouts. Stiles look at the bat in his hand and turns to hide next to the door. Derek realizes he isn't following and turns back, shouting his name. When the Melded Wolf bursts through the doors, Stiles hits him over the head with the bat, shattering it to splinters (NOTE: This would mean Stiles swung with a tremendous amount of force, not just that the twins are strong). The Werewolf roars at him, and Stiles edges away. Scott jumps up and claws free one of the lighting fixtures so it swings down and hits the twins.
Allison and Isaac are still at the school. Isaac reports that he can't get a hold of Derek or Scott. He asks how Lydia is. She's got bruising on her neck and is being taken to a different hospital in Beacon Hills since Beacon Hills Memorial is being evacuated. Isaac is surprised that the storm is that bad. Allison further explains that the backup generators at Beacon Hills Memorial might not be able to handle it if the power goes out. Isaac is concerned about leaving Cora alone with Peter and insists on going to the hospital even after Chris shows up to take the two of them home. Allison gives her dad a look until Chris agrees that they'll all go. The power in the school goes out.
Back at the hospital, Melissa finds Deucalion's cane stuck in the wall. She pulls it out, and then Deucalion eases it from her hands. "Thank you, Ms. McCall." She knows who he is. "The bad guy." He replies, "You have no idea," and both his and Kali's eyes glow red.
In silhouette, the twins separate. Aiden accuses Ethan of hesitating, but Ethan says that he pulled back, which is different. Aiden says they're protecting Jennifer. "They don't have a choice!" Ethan argues. "Neither do we!" If all the sacrifices she's been making are going to give her the power to get rid of the alpha pack, then they need to get rid of her first. The backup generators click on.
Peter, Stiles, Scott, and Derek head into an exam room. Peter puts Cora down on a gurney and asks about the twins. Derek tells him they're close. Stiles asks about Ms. Blake, and Scott just shrugs. "What does that mean? Like, she's gone? Scott, are you kidding me?" Derek shushes Stiles, and Stiles gets up in his face. "Me be quiet? Me, huh? Are you telling me what to do now? When your psychotic, mass murdering girlfriend--the second one you've dated, by the way--has got my dad somewhere, tied up, waiting to be ritually sacrificed?" Scott steps in to quiet Stiles down and points out that the twins are still out there. Stiles says that since Ms. Blake is gone both his dad and Cora are dead. "Not yet," Scott insists. He asks Peter if Cora is really dying, but all Peter can tell him is that she's not getting better. Scott says that there has to be something they can do. Jennifer comes into the room then. "You can't. Only I can save her, and I can tell you where Sheriff Stilinski is. But there is a pack of alphas in this hospital who want me dead." She'll help them, but only when she's out of the hospital and safe. Derek launches himself at Jennifer, throwing a table down across Stiles's path. Scott holds Derek back. "She was trying to get out!" Derek says. Jennifer claims that she was just trying to stay alive. Stiles asks her to heal Cora to prove that she's one of the good guys, but Jennifer refuses. "I'd like to volunteer a different method of persuasion," Peter says, "let's torture her." "Works for me," Derek replies. Just then Melissa's voice comes over the PA system. "Deucalion requests that you bring the woman calling herself Jennifer Blake to the ER reception. Do this and everyone else can leave." They have 10 minutes to comply. Jennifer says that Deucalion won't hurt Melissa and Scott knows why. Derek asks Scott for an explanation. When Scott doesn't say anything, Jennifer answers for him. Derek isn't the only one Duke wants in his pack.
Chris, Allison, and Isaac arrive at the hospital. Allison asks Isaac if he can catch any scents, but the heavy rain is washing everything away.
Jennifer explains that Deucalion wants a perfect pack, which means adding the rarest of alphas to his ranks. Peter realizes she means a True Alpha. Stiles asks what that is. "The kind that doesn't have to steal his power from another," Peter replies with a look at Derek. "One that can rise by the force of his own will. Our little Scott." Scott decides that it doesn't matter what Deucalion wants, they still have to get Jennifer out of there. Stiles asks about his mom, but Scott just keeps talking. There was another ambulance in 20 minutes from the time they walked in, so if they can get to the garage, they can all get out. Peter points out that the twins won't just let them leave, but Scott offers to distract them. Derek says that he'll help him, but Jennifer declares that she's not going anywhere without Derek. Peter offers to help Scott instead, but he's going to need something better than a baseball bat. They all start looking around the room for something to use. Stiles picks up the paddles to a defibrillator. "What about these?" Derek looks over at him. "Do you know how to use those?" "Well, no." "Put 'em down." Stiles nods and does. Scott finds a needle of epinephrine. Derek tells him that's only going to make the twins stronger. Peter stops and stares at Scott. "How strong?"
Next thing, Peter bursts through the doors like a zombie with the needle stuck out of his chest. He pulls out the needle and drops it. He and Scott face off against the twins. "All right, boys. Let's rumble." While Peter and Scott fight the big guy, everyone else makes a run for it. The ambulance is still in the garage. They open the back of the ambulance, and Derek places Cora on the gurney inside. Jennifer calls Derek over and shows him the dead ambulance driver. Julia," Kali's voice echoes. She has the keys to the ambulance. Jennifer steps back behind Derek but warns him he can't beat Kali on his own. "That's why we're gonna run," he says. They do, leaving Stiles in the ambulance with Cora. They get into the elevator just in time to escape from Kali. The power flickers, and then the elevator stops as Deucalion throws a switch on the roof.
On the roof, Melissa asks Deucalion what he wants with her. "You're my gesture of goodwill." He tells her to go find Scott and lets her leave.
Inside the ambulance, Stiles locks everything up. He asks Cora how she's doing then asks why she looks like she's not breathing. He panics a little and then starts stepping himself through giving her CPR.
Derek opens the elevator door, but they're not near enough to a floor to crawl up and out. He looks up at the ceiling, but Jennifer tells him that the emergency hatch bolts from the outside. He'd have to break it to get them out, which would just draw attention to their location. Derek points out that Kali already knows. Jennifer says that Kali knows they got in the elevator but doesn't know that they didn't get out. Derek still wants to try breaking out, but Jennifer says that if he ends up fighting alphas in an elevator shaft she'll be dead. "Then someone needs to get the backup generator running again," Derek says and takes out his phone.
Stiles continues the CPR, begging Cora to wake up. She eventually gasps, and Stiles sits back. "You know next time I put my lips to your mouth, you better be awake."
Peter and Scott run, and Peter falls and slides into a wall. He complains that the epinephrine shot didn't last very long as Scott hauls him up. They hide in the laundry room. Scott asks Peter how they're supposed to get past them. "Personally, I think if we keep letting them beat the living crap out of us, they'll tire and give up." Scott then sees the laundry chute. He drops Peter through, and then goes right after, landing on top of him. "You couldn't wait like 10 seconds?" Peter gripes. Scott gets a text message from Derek. Peter doesn't even have to ask to know that the others didn't get out. Scott texts Derek back not to move and that they're on their way.
In the ambulance, Stiles talks to Cora, even though she's unconscious. He assures her that Scott will get them out of this, even though he can't believe he just said that. "You know, I actually used to be the one with the plan. Well, or at least a Plan B." Now he thinks that maybe Cora was right when she accused them all of being useless. "Maybe all we really do is show up and find the bodies." He pauses for a second and tries to hold back tears. "I don't wanna find my father's body." There's banging outside, and Stiles sees the Melded Wolf stalking around the ambulance.
Chris, Allison, and Isaac move through the hospital. Chris cocks his gun, which Isaac takes as a bad sign. Isaac hears something below them and gets on the floor to listen better. He hears two pairs of footsteps.
Inside the ambulance, Stiles hears footsteps as well. Scott and Peter suddenly appear at the window, and Scott orders Stiles to open the door. Peter is crashing so hard that he can barely walk. Stiles hauls Peter into the ambulance and tells Scot that Kali has the keys to the ambulance and the twins are very close by. They both look toward the sound of distant banging, and Scott tells Stiles to stay put.
Scott is in the hallway by himself, listening carefully. He hears something drop, and then the twins attack. They pin Scott up against the wall and demand to know where Ms. Blake is. "We're trying not to hurt you!" "Try harder," Scott grunts. Melissa shouts at them to get their attention, and they drop Scott. "I'd like to try something," she says, then hits them with a pulse from the defibrillator. The shock knocks the twins apart, and Scott looks up at his mom in awe. Together, they run for it.
Derek stares at his cell phone, both avoiding Jennifer and waiting for an update. "Anything?" she asks. He ignores her. She tells him she knows what he's thinking. "That I'm using you, that everything that has happened betwee us is a lie, or that I'm evil. A bitch." She hopes he's not thinking the most superficial thing, which is thought. "Is that her real face?" Is the slashed, mutilated face he saw thanks to the mistletoe what she really looks like?
Kali and Deucalion are in the morgue. Kali argues that he should have kept Melissa. She thinks Duke has a soft spot for Scott. "I have an investment I'm trying to mature," he says. He then tells Kali that if she wants to talk about soft spots they can talk about Jennifer Blake. That gets Kali to back off. She calls Ms. Blake by her real name, Julia Baccari.
Jennifer tries telling Derek her real name, but he doesn't care. She admits that she probably should have picked a new name with different initials, but that she read somewhere that people pick new name that are subconsciously derivative of their original names. It's a way of not completely letting go of your identity since your name is tied to your sense of self. She says that your face is also tied to your sense of self and talks about looking in the mirror at a hacked up atrocity should couldn't recognize. Derek still studiously does not care. "But I bet you're curious." She thinks he must wonder exactly what happened. Derek finally looks at her. "You were an emissary. They tried killing you along with the rest of the pack. Mystery solved." She corrects him. "I was Kali's emissary. And I was the one she couldn't kill." In a flashback, Julia falls to the ground with slashes across her face.
Kali tells Duke that she didn't understand why she had to kill Julia, too, since she was harmless, but she did it because Deucalion asked her to. "I did everything you asked to be a part of this pack." He counters that she really did it to be with Ennis and that Julia isn't looking so harmless now. Kali thought Julia was dead. She says there was a moment of uncertainty when she turned back and saw Julia lying perfectly still but focused her hearing anyway. "Listened to the sound of her heart still beating, still fighting for life, and I thought, 'I could go back and finish it, or I could let someone I love die peacefully.'" Slashed and nearly dead, Julia dragged herself toward the nemeton. Its power had been virtually gone for years. But a few months earlier, something happened that gave the nemeton a spark of power again. The sacrifice of a virgin. When Derek killed Paige in the root cellar, he gave the nemeton power. And, subsequently, gave Julia enough power to keep from dying before she could be found by Sheriff Stilinski.
Melissa tells Scott that Deucalion just let her go, but Scott doesn't believe Duke would do it without a reason. Scott hears a gun click and comes around the corner slowly to find Chris, Allison, and Isaac.
Jennifer asks Derek if he knows why people kiss under mistletoe. He says no, even though he's trying not to have to talk to her. She explains that it's a Norse myth. Baldur the son of Odin was the most beloved by the other gods. They wanted to protect him from all the dangers in the world. Frigg took oaths from fire and water, metal, stone, and every living thing that they would never hurt Baldur. At a gathering, they tested him and nothing worked. But there was one god who didn't love Baldur quite so much: Loki. Loki learned that Frigg had forgotten to ask mistletoe, a tiny, seemingly harmless plant that got overlooked. Loki made a dart out of mistletoe, and it killed Baldur. Frigg declared that mistletoe would never again be used as a weapon and she would place a kiss on anyone who passed under it. Jennifer says that we hang mistletoe on our doors during the holidays so it will never be overlooked again. We were the overlooked: the emissaries. She believes this is was Deucalion and the alphas' mistake. She made an oath of her own to use the power from virgins, healers, warriors, philosophers, and guardians to destroy the alpha pack--so that their monstrous actions would never be overlooked. "You killed innocent people," Derek tells her. "So have you," she shoots back. "I know the real color of your eyes, Derek, and I know what it means." He frowns as she asks him to help her stop the alphas from ever hurting anyone again. He tells her that she can't beat them, but she isn't so sure. "Boyd asked you right before he died what happens to a Werewolf during a lunar eclipse?" He never got the chance to tell him, but she's pretty sure Derek knows. "We lose all our power." And she smiles.
Chris, Scott, Melissa, Isaac, and Allison discuss Derek and Jennifer being trapped in the elevator. There's no way to get them out without turning the power back on. The problem with that is that the sound of the elevator will draw the alphas to Derek and Jennifer, and they have to avoid fighting the alphas. Scott insists that Jennifer's life is too important to risk because she's their only way to save Stiles's dad and Cora. Chris says he isn't sure which teacher this is. Isaac tells him she's got brown hair and is kinda hot. Everyone stops to stare at him. Allison looks at her own reflection and claims to have an idea. Kali asks Deucalion what Scott and his friends are doing. "Plotting," he replies, looking amused.
The twins are still stalking the hallways. Scott texts Derek that they have a plan. Derek opens the elevator doors, making a noise that catches the twins' attention.
Isaac is in Chris Argent's car. He has a video chat open with Allison. She asks if he's ready and he says yes. She asks if he's nervous. "Do I look nervous?" Allison lies and replies that he doesn't, then sets the phone down. "Did he look nervous?" Chris asks Allison on the other end. "Terrified," she answers. "Yeah, I can still hear you, very, very clearly," Isaac says to them. He's supposed to drive as soon as he sees the twins in the phone's camera.
The twins check around but think they're on the wrong floor. They hear footsteps of a woman running and race to find her. As soon as Isaac sees the twins, he guns the car. Kali leaps out of a window and lands just as the twins follow Allison out of the hospital. Allison turns and fires some arrows. Chris opens fire with his pistols as well. As the alphas scatter, Melissa turns the power back on up on the roof. As soon as it's back, Derek hits a button to get the elevator moving. "Derek, please look at me," Jennifer says. She has her glamor down and screams.
Isaac pulls up to the ambulance, and Peter and Stiles transfer Cora. As he's closing the door, Stiles reads the bottom line of a medical history sheet where it says: Parent or Guardian. Suddenly, he realizes that guardian doesn't mean law enforcement, it means parent. Rather than go with Isaac, Stiles takes off looking for Scott.
Scott goes to the elevator to find Derek unconscious on the floor and the emergency hatch broken open. Scott realizes that his mother is in trouble and takes off to find her just as Stiles runs up. Stiles calls after him, but he doesn't stop so Stiles runs to catch up.
Peter urges Isaac to drive, but Isaac won't go without Scott. There are gunshots, but Isaac still doesn't go. Then the twins appear in the rearview mirror and Peter yells at him. "For the love of God, go now!" Isaac finally peels away.
Scott races to the roof. "Mom! Mom!" "They're gone," Deucalion says. "Guardians, Scott. If you were with me, I could've told you what it meant. I could've warned you." Deucalion makes Scott an offer. If he helps him catch Jennifer, Duke will help Scott get their parents back. Scott wavers and starts to cry. He gives in to Duke. Stiles arrives and begs him not to go with the alpha pack, but Scott doesn't know what else to do. "Scott, there's gotta be something else. We always--we always have a Plan B." Scott shakes his head and goes with Deucalion, promising Stiles that he'll find his dad.
Melissa wakes up tied to a post in the root cellar. The Sheriff is there as well and asks her if she's okay. Melissa asks where they are, and he tells her that Jennifer called it a nemeton.