The episode opens with a man, who will be called "The Chemist" for ease of identification, who has a werewolf in a ring of mountain ash. He sips tea and listens to the same tape as Scott and Stiles that details how to receive payment for completing kills on the deadpool.

Scott doesn't understand anything they're going through and vocalizes that to Stiles as he hurriedly shoves the money back into its bag. Stiles asks what he's doing, and Scott says he's not doing anything, since the money is Derek's.

"Derek's and Peter's," Stiles corrects, and when Scott asks what that means, Stiles continues "It means maybe we should proceed with caution."

"You don't think we should tell Derek?" Scott asks to try and clarify, adding "Not telling Derek includes not telling Noel. You really think that's a good idea?"

"No, no, no," Stiles trails off, standing and facing away from Scott. "Of course we have to tell Noel, and of course we have to tell Derek, I'm just..." He stops to contemplate and heaves a sigh, finishing "I'm just saying, some of that money is Peter's, right? Right? Peter, homicidal killer, remember? You wanna give half a million dollars to him?"

Scott watches him speak, asking slowly and purposefully "We should give Derek his money back, but not Peter?"

"I didn't say that," Stiles defends, Scott asking "Stiles, what are you saying?"

Stiles doesn't respond before there's a knock on Scott's door, and he hurriedly shoves the bag of money under the bed before the knocker can enter. Malia steps into the room, announcing "We found Satomi's pack. Noel and Derek and I. But they're dead."

"All of them?" Scott asks in disbelief, Malia amending "All the ones we found."

"Where are Derek and Noel?" Stiles asks seriously, and we see the pair with Braeden, entering the hospital with Braeden in Derek's arms. Derek yells that Braeden had just been shot, and we see that Noel's arm is covered in black veins from taking her pain as he has a hand laid on her knee.

—

At the clinic, Deaton fights off an attacker in a raincoat, and when they hit a stalemate he says "You could have called, Satomi-san."

Satomi looks up and her eyes glow red as the intro plays.

—

The next day at school is the PSAT, and our main teens (minus Liam and Lydia) wait in line to take it. Kira asks where Lydia is, Stiles answering that she took it her freshman year.

"Does that mean I could've taken it some other time?" Malia asks, Scott assuring her that she studied harder than any of them.

"Doesn't mean I'm gonna do good," she argues as Stiles adds "Well..."

"Well?" Malia asks, Noel answering as he elbows Stiles' side "Do well. He's correcting you. Which really isn't what you need right now."

Kira resolves that it's only three hours, and that they can all survive three hours. They check in and give fingerprints to the Chemist, who we now see is a teacher who is administering the test.

Natalie Martin takes Scott's phone, and as she takes Noel's, she smiles and says "You'll get it back after the test. Oh, and your last few boxes of things are in the downstairs study. Just stop by and grab them whenever you can, you can leave your key on the desk when you take the last one, okay?"

Noel looks wounded that that's what she chose to say to him, but he nods anyway and goes to find his seat.

The Chemist goes over the parameters of the test, and Natalie goes to find Coach, since he was supposed to monitor the test. She finds him, apparently drunk and passed out in his office, and she laments that he fell off the wagon at school of all places after fifteen years of sobriety. She goes back to the classroom and is told she'll have to be a monitor herself as the test begins.

As we see shots of our main teens, either struggling or thriving, tense but upbeat music plays. It eventually cuts out entirely, and a girl faints behind Stiles. Natalie helps her up, as she admits that she got dizzy. She sees a rash on the girl (Sydney's) arm. The Chemist asks if he needs to stop the test, to which Natalie says no and Sydney sits back down. She takes her phone and leaves, telling the teacher that no one leaves the room as Scott turns and looks at Sydney.

Natalie goes down the hall and checks on Coach, finding him with sores and rashes all over his back as she stops a group of students from entering the school. She locks it down, and the class rushes out to see what's going on as Natalie tells them to return to their seats.

Once they're all inside, Natalie calls someone on the phone and asks for the number for the CDC, Scott and Noel stopping in their tracks and listening.

—

After the break, people in hazmat suits enter the school and set up a testing site/quarantine zone. The sheriff looks on from outside, and asks an agent what's happening. She tells him that they're putting the school on a total quarantine, and inside Natalie instructs Scott and Noel that they're isolating the sick and awaiting instruction. She leaves Scott and Noel with a sniffling Sydney, and Scott greets her with a promise that she'll be okay.

"It's not that," she says, looking down at the spreading rash on her arm. "The PSAT is the qualifying test for the National Merit Scholarship. My parents can't afford to send me to college without it."

"Hey... I'm sure they'll let you take it again. If this isn't an outstanding circumstance I don't know what is," Noel assures her and pats her leg, and she nods to thank him as Scott watches them. They both duck out together after sharing a worried glance, and we return to the other three still in the classroom hypothesizing about what could be happening.

Stiles goes to grab his phone, but the Chemist tells him not to bother, as all outside communication will have been cut off by then.

—

At the clinic, Deaton tries to help a member of Satomi's pack, but tells her that he needs to be taken to the hospital. He assures her he knows someone trustworthy to handle werewolf aligned patients, and we see Melissa at the hospital exiting an elevator.

—

Derek sits with Braeden, typing angrily on his phone and looking annoyed. When Melissa comes in, he leaves his chair and lets her in next to Braeden, as she asks "What's got you so worked up?"

"Noel's not answering any of my texts. It keeps telling me they're not even getting through to him," Derek says, sighing. Melissa turns and looks at him, saying "He and the others are taking the PSAT today, I'm sure he doesn't have his phone on him. That's why I'm giving her this."

"What is it?" Derek asks, and she explains that it's to wake Braeden up.

"I thought you said she needed to rest," Derek tries to get clarification, and Melissa says "That was before I found out the CDC just put the high school under quarantine with the boys still in there."

Derek looks nervously at Melissa as Braeden suddenly awakens, breathing hard as Melissa tries to calm her. "Braeden, look at me. You were shot, but you're in the hospital now, and you're fine. Do you understand?"

Braeden looks at Derek, and then beside him, seeming confused before she nods.

Satisfied, Melissa asks "Okay... Last night you were in the woods, and you came across another pack? Do you know what happened to them?"

"I-I told you, they were poisoned," Derek says, still distraught at the quarantine news, but Braeden corrects him "No... No, they were infected. It was a virus, designed to kill werewolves. And it did... It killed them all."

—

Back at the school, Natalie knocks on the door of the locker room, saying that Noel and Scott have 'been in there for a while' and need to get back to the others.

Inside, they stand at the sinks, Noel's head in his hands as he hunches over the sink and Scott grips the one beside him. Neither of them are capable of speaking, the camera flickering around them haphazardly to show how confused and detached they both are. Scott opens his mouth as if to roar, but no sound comes out, his fangs on prominent display as Noel's fingernails grow into claws and he rakes them down his face. He doesn't break the skin, but the frustration and disorientation behind the action is clear as he and Scott look at each other and we cut to a break.

—

Lydia has a scene in the lake house where she goes through Meredith's belongings to try and establish a connection and posthumously get her help.

Back in the locker room, Noel and Scott breathe hard, and when Mr. Yukimura enters the room, the boys simultaneously say "Get Stiles."

—

Kira and Malia get their blood drawn and Kira causes an electric spark that nearly burns through an agent's hazmat suit. Outside, McCall asks for information since his son is inside, and the sheriff catches him up to speed and suggests that it's a planned attack.

—

Scott's eyes glow red, and Noel's glow gold as they look at each other with sweat dripping down their faces. Their eyes both flicker out occasionally, but always come back to their glow. "No... You can't hold it," Noel says wearily, and Scott says sadly "Neither can you."

"I can't make them go back," Malia says about her claws, showing them to the rest of the group.

"Obviously the virus is affecting the three of you in a way that it won't affect a human being," Yukimura says, as Stiles says that the three of them need to stay out of sight and be quarantined from the quarantine.

"Where? What if they get violent, like on a full moon," Kira asks, Scott suggesting "We shouldn't stay in here, not in the locker room."

"A classroom is not gonna hold us," Malia says with a shake of her head as Stiles suggests "What about the basement supply room? Where you put Boyd and Cora?"

"Too many ways out. We need something secure, where no one can find us," Scott says, and Noel supplies weakly "The Hale vault? Knowing them, there's a way to get to it from inside the school, well hidden enough that a human wouldn't be able to find it."

All in agreement, Stiles gets his hands on blueprints of the school, and in the middle of his explanation, he gets woozy and nearly falls over. Yukimura sees the rash on his arm, and tells them that even if the virus isn't affecting Stiles like it affected the wolves, he's still getting sick.

"I don't feel sick," Kira argues, but her dad suggests that it's affecting her neurologically instead. He pulls out her PSAT test form and shows that all of her answers were bubbled in off the line.

—

The group tries to find the entrance to the vault, and all throughout, Noel appears to get weaker and weaker. Stiles ends up finding an inscription on the wall behind some cart, and he looks at the mark and tells them it only opens with claws. Softly, he asks Scott without asking anything "It opens with anyone's claws."

Scott shakes his head, and nervously, he asks "Noel... Can you do it?" Noel knows the implication, that only a Hale can open it, but he says "I'm not, I can't."

Stiles steps closer to him, saying "You are, you've got the freaking tattoo and the ghostly memories to prove it, so can you at least try? So we can avoid making a big situation any bigger?"

Noel looks over his shoulder at Malia, and whispers in a voice so quiet only Stiles can hear it "I'm not the scapegoat for your dirty little secret."

Despite his biting words, he approaches the wall, claws on display. He slots them into the holes and they glow in response, proving he's qualified enough as a Hale to access the vault. Before he can fully feel excited about this development or unlock the vault, he stops, and his eyes roll back as he collapses from his sickness. Scott rushes in and catches him, holding his face and saying his name. Noel's lips and eyes twitch, and Scott says "I... I think he's okay... But..."

"Hey, I can do it," Malia offers, showing that her claws are still out. Stiles looks relieved that she's willing, but Malia then says "I can do it if you tell me what you've been hiding from me. I know you think you're trying to protect me, but I can handle it."

She makes a 'go on' gesture as Scott holds Noel, whose breath is ragged but even. Before either of them can confess, Malia says confidently "I know I'm on the list. Me and Noel, right?"

Almost relieved, Stiles confirms that for her. Malia asks how much she's worth, and Scott tells her that she's worth four million. She spaces out for a second, and when Stiles asks if she's okay, she asks "What about Noel?"

"Six. We think he's worth more than a regular beta because of all the stuff that happened with Laura, we told you about that," Scott says, as Noel starts to wake up in his arms.

Malia nods, saying "I'm... Yeah. Wow. Okay. I mean, Scott's worth 25, Kira and Noel are 6, they're gonna take you guys out way before me."

She then approaches the vault and unlocks it, and they all enter with Scott half carrying Noel as he wakes up. The door closes behind them, and as the music builds, Noel says with a laugh "Cool."

Blackout.

—

At the hospital, Melissa tries to help Satomi's pack member, but he dies in the elevator before she can do anything for him. Back in the vault, Noel sits against the wall as Kira paces and Scott sits on some boxes. Malia is laying in Stiles' lap, and Stiles says that this is where it all started. He points at the vault, explaining that that's where the money was, 117 million in bearer bonds.

"How do you even change bearer bonds into cash," Kira asks, Noel explaining "It's not easy, I can tell you that. Bearer bonds are practically extinct, it's hard to find anyone that will deal in them since they're so outdated. But if you can find a bank willing to deal with them, you can cash it sort of like a check."

"And they just let it sit here and collect dust. 117 million dollars," Stiles says almost like he's annoyed. Kira asks why it matters that they let the money sit, and Stiles asks "Do you know how many problems that money could have solved?"

"For you?" she asks, Stiles saying for him and his dad. The bills from Eichen House and his MRI are crushing [the sheriff], as Stiles puts it, the rest of the teens looking tense. Scott cuts in, saying "My mom does this thing. She writes down all the items in our budget, how much they cost, and then she adds it all up and figures out how long we have until... We lose the house."

Noel closes his eyes, looking pained, either from his illness or from his friends' words. He opens his mouth to speak, but Stiles stops him. "We know, you wish you could take a piece of your inheritance. You've only told us a thousand times."

"No, not that," Noel says and rests his chin on his knees. He frowns, saying "As wealthy as we were, when my dad died, he had a ton of unpaid medical bills. Not because of a lack of money or anything, but things went to collections faster than my mom could handle while dealing with her grief. She was still working to pay it off when she died, and I had to listen to my uncle on the phone telling the debt collectors that they can't legally hold an eleven year old responsible for his late parents' unpaid debts."

Scott looks at the very least sympathetic, as Noel continues "Eleven years old... Freshly orphaned... And all they cared about was getting payment from me for my dad's MRIs and scans and blood work that didn't even save him in the end. When did people stop being people and start being sacks of cash to fill pockets that are already rich?"

Tears brim his eyes as Noel finishes his speech, Stiles and Kira's eyes cast downward.

—

The sheriff and Lydia have an extremely brief scene before we go back to the vault.

—

Scott has his ear pressed to the wall, informing the others that people are looking for them. He says that someone is going to have to go up, as all three boys turn to look at Malia and Kira. Malia's breathing is ragged, and Kira is concerned for her friend as Noel says with finality "You have to tell her about Peter. Or I will."

"You don't even like her," Stiles argues, but there's hardly any bite to it, Noel replying with the same serious but casual tone "I don't have to like her to think she deserves the truth. You think you can just keep her eyes off the deadpool forever? She's going to see it. Isn't it better that you warn her before she does?"

"What about the fact that Peter's name is the only one missing from that list?" Stiles asks, stepping closer to Noel. Noel's eyebrows knit, as Stiles continues "That makes him either incredibly lucky, or the benefactor. When she finds out about him, she's gonna go to him, you know she is. And then he's gonna twist his way right in like he does with everyone, including us. We let him walk around like nothing ever happened, like he's one of the good guys, but he's not, Noel, he's not one of the good guys. If she finds out about him, she's gone, and that's probably what he's waiting for. He wins, we lose."

"Stiles, we're already losing," Scott finally responds, as he holds up his hand and shows Stiles the blood on his nails from failing to grow.

—

Deaton and Melissa learn what the wolves are infected with, but Deaton says that without an antidote, they're all going to die.

—

After returning from break, Stiles wakes Malia up gently and feels her temperature. She wakes up as Stiles tells her he's gonna be leaving for a bit. She asks where he's going, and he says that since it's worse for her and the others (we see Kira comforting a woozy Scott and Noel with his forehead tucked into his knees for emphasis), he's going to go and try and get information on what assassin is trying to kill the supernaturals.

He gives her one of his jackets, and he promises he wouldn't leave her behind before kissing her forehead and heading off. On his way out of the vault, since he sits by the door, Stiles gives Noel's hair a tousle before taking a glance back at Malia and leaving.

—

At the hospital, Braeden rests and Derek watches over her. When she wakes up she asks him what he's still doing here, adding "Shouldn't you be at the school, plotting your boyfriend's escape from quarantine? You could carry him out bridal style, all heroic, or pull a King Kong and hold him in one arm like a rabid caveman."

"All tempting," Derek admits cooly with a laugh, "but there's nothing I can do down there. I already tried while you were asleep, he's locked down tight. I figure if I can't get to him, I'll trust the sheriff and the CDC to do their jobs and come back here to protect my investment. I've got a lot of money riding on you."

Braeden chuckles, and Melissa enters the room with Satomi, telling Derek that there's someone she thinks he's been looking for.

—

Lydia tells the sheriff that she knows somebody is going to die in the school, and we go back to the hospital where Deaton tells Derek and Melissa what's happening at the school. He cites that an outbreak of canine distemperate killed 40% of Yellowstone's wolf population a few years ago, and Melissa asks what it's going to do to their wolf population.

Deaton explains that the virus has been altered to infect faster, Derek supplying with worry in his voice that it was weaponized. Satomi agrees, since it infected her entire pack, but Deaton points out that it didn't infect her. He asks if she wasn't infected, or if she's possibly immune.

—

Stiles asks Natalie in the quarantine room where Mr. Yukimura is, and when she tells him he's helping the other students, he turns to leave. Before he can, he notices that Coach is in one of the beds, asking if he's the only adult that got sick. Natalie confirms that to the best of her knowledge he is, and Stiles tells her he'll be back as he rushes out wondering aloud why Coach is the only one.

—

"If your pack was infected, then who was doing all the shooting at the entrance to the woods," Derek asks, as Satomi answers that it was probably another assassin. She tells them that she'd rather deal with that than fight this mystery illness, and then goes silent as she looks at Derek. She apologizes, telling him "I just noticed how much you remind me of Talia."

He hides a ghost of a smile as Satomi explains that she used to visit Talia and asks gently if Derek remembers her. He says that he remembers the tea Satomi would bring, and she explains that she used to bring the tea as a gift because his mother loved it.

"What kind of tea," Deaton asks, and Satomi explains that it was reishi tea. Deaton tells her that reishi is a very rare but very powerful remedy for sickness, and that she didn't get sick because she was inoculated.

"How rare is it? Can we find it?" Melissa asks, and Derek says with evident relief "We don't have to. My mother kept some of it, it's in our vault."

—

We see the jar of reishi in the vault as Malia twists uncomfortably on the ground, finding a slip of paper in Stiles' pocket. She opens it, Scott warning her not to and weakly standing to stop her.

When she gets the paper open, Noel calls out her name nervously, wrapped up tight with his arms around himself. She shakes her head and breathes hard, telling the boys that she can't see.

Scott's vision seems to be wavering too, as we see his POV and things flash in and out of focus.

Stiles races to find answers in the coach's office, and notices the black fingerprints on Coach's mug. He draws the connection between the black prints and the ink pad they used to give their thumbprints when they signed in for the PSAT, as the Chemist comes in and tells Stiles that he's wondering where the others are.

He then holds up a gun, mentioning that he needs to show the benefactor proof that they're dead to get his money, and then he turns the gun on Stiles as we cut to black.

—

The humans that were infected start to wake up and their rashes clear, as they climb out of bed and exit their rooms of quarantine.

—

In stark contrast, in the vault, the four who stayed behind look terrible. All have dark circles around their eyes and are breathing heavily, and none of them have any vision now. Malia asks what's happening to them, Kira tells Scott that she can't see, and Noel bunches his hands up in his hair and keeps his eyes closed as if he's in denial of his condition.

Scott rises to his feet shakily, looking around as if for a solution as we cut back to Stiles. To summarize, the Chemist asks Stiles where the others are, but Stiles refuses to tell him. The Chemist keeps the gun on him, right at his forehead, giving him three seconds to speak. Once he gets to three, a gun fires, and Stiles' face is splattered with blood as McCall saves the day and kills the teacher. He quickly tells Stiles where the antidote is, and tells him to go inform Scott despite not knowing what any of it means.

—

Derek tells Satomi that he has to get to the school, but she asks about the others at lookout point. Before he can respond, a women exits the elevator, and opens fire on the two of them.

Derek dives out of the way, and Satomi has enough time to react and stab their attacker in the neck. She tells the stunned onlookers (Derek, Melissa, and Deaton) that while she learned to control her anger, she knows when to use it.

—

Desperately, Stiles yells through the door of the vault that the cure is in there with them, pounding on the door as Scott continues to struggle on his feet. He falls to the floor as Kira tells him that she saw the mushrooms when she was looking around, and Scott lets his eyes glow red with renewed strength. The girls writhe on the ground and Noel stays propped up against the wall, all close to losing consciousness as Scott sees the purple mushrooms glowing on a shelf.

He crawls to them and knocks them off the shelf, the glass shattering and the powder from the mushrooms filling the air. He inhales deeply, and the vault door opens.

Stiles scrambles away as Noel's arm falls out of frame, collapsing face first onto the floor after opening the door as Scott tumbles through to come face to face with Stiles. The two embrace, and we see crowds of people leaving the school.

—

Lydia runs to her mom and the two hug, as we go back to the vault. Scott helps Kira up as Stiles runs to Malia, Noel in the background on his own trying to catch his breath. Malia stops Stiles from touching her as she stares at the deadpool, walking out of the vault as the episode ends.