In a conversation with Theo, Scott explains that five days have passed and that his reliance on his inhaler has increased.

A feeling of dread and foreboding seems to permeate the halls of school and everyone can sense something is coming.

There is a separation between the members of his pack as well. Scott says they are not talking to each other and sometimes don't even notice each other.

Scott senses that not talking makes it easier to keep secrets. We see Malia with pictures from her investigation of the Desert Wolf.

Scott says he doesn't know if his friends are lying about things or if it's more "lies of omission" as we see a shot of the wound on Stiles' shoulder from Donovan's "hand mouth".

Scott believes the worst lie is to Stilinski because they've yet to tell him about Parrish taking the chimaera bodies. They've also not told Parrish.

The Deputy is given a new name tag with "TRY NOT TO LOSE THIS ONE" written on the envelope. Scott explains that Parrish doesn't seem to remember taking the bodies and they believe he is only dangerous if someone tries to get in his way.

Lydia and Stiles are trying to find the Nemeton and the chimaera bodies they believe Parrish dumped there but Scott says finding the tree stump isn't easy. He relates the story of the "surrogate sacrifices" they used to find the Nemeton when the Darach took their parents.

Scott explains that the Sheriff has tasked all his deputies to track down and question every potential chimaera going off a list of those who had transplants or had, in some other way, become genetic chimaeras (two sets of DNA) through conventional means.

Deputy Clark has a clipboard with a "Dissociative Experiences Questionnaire" attached. Some of the questions visible are:

Have you experienced fugue states or incidents of missing time? During the past month, have you had any reason to wonder if you were losing your mind or losing control over the way you act, talk, think, feel, or of your memory? How much of the time, during the past month, have you been a very nervous person? During the past month, have you been in firm control of your behaviour, thoughts, emotions or feelings?

Scott says some of the deputies believe they are hunting a serial killer.

Deputy Clark sees her sister 's name on the list of those to be questioned. The other names visible include Rusty Andrews, Tom Owens and Chris Cook.

Scott says both Hayden and Corey are doing okay, healing fast and getting stronger. The cut in Hayden's side has healed. Scott says "they don't need our help." He says he doesn't believe they want his help anyway.

He still hasn't heard from Kira. Scott has placed a "Closed Until Further Notice" sign in the window of the animal clinic and says he is getting more and more worried about Deaton.

At the clinic, holding his inhaler, Scott tells Theo that he knows something is coming. He wonders how good he will be when it comes if can't even breathe.

Theo says Scott sounds like he is apologizing and Scott says he knows Theo was looking for a pack and he's just sorry that he found him.

Scott asks Theo if he still wants to be part of the pack. Theo says he's with them for better or worse and Scott says it's going to get worse to which Theo says, "I'm counting on it."

~~~

The Geneticist, with a syringe, withdraws fluid from the large, body-holding, tank in their lair. The dead body of a teenage boy lies on the examination table with a spike stuck through its back. The Geneticist walks over and injects the liquid from the syringe into the Surgeon's arm. The arm, which seems "frankensteined" from more than one body, is scarred and withered. After the injection, the flesh begins to plump up immediately and is soon restored to full vitality.

Theo tells them that he needs more time. They say "Perigee syzygy." "The "supermoon." "We'll know at Perigee syzygy." The Surgeon is looking at four charts on a lightbox. They each show the moon or the phases of the moon.

(The perigee-syzygy of the Earth-Moon-Sun system, known colloquially as the "supermoon," is when the moon is full or new at the same time it passes closest to the Earth. The moon appears larger in the sky and there is a very small, but measurable, increase in tidal forces)

Theo says he needs Hayden alive but the doctor says she is a failure and "Failure compromises the experiment pool."

Theo is angry. He says he's kept Scott out of their way, given them Selene and that they promised him a pack. The doctor says they promised him nothing. He yells at them that he needs Hayden alive and they all turn on him. He takes a step back and they agree to allow Hayden to live until the "perigee-syzygy."

The Surgeon retrieves the spike cane from the body on the table and re-sheaths it with a snap. The handle of the cane is a hammer.

~~~

Stilinski and Deputy Parrish examine the house where Hayden and Liam were held captive. Parrish says it doesn't look like an operating theatre and speculates that it might be a "remote field station."

As he shines his flashlight over the mercury liquid splashed over the floor and walls he decides to equip every deputy with ultraviolet light to try to identify the chimaeras.

~~~

Liam and Hayden share a moment alone between the busses in the parking lot at school.

He's checking on her after every period to make sure she is safe. She says the Dread Doctors only come out after dark and believes she will be safe at school. She tells him that he doesn't have to check on her but he says he wants to and proceeds to kiss her. After a bit of kissing, they break and Liam has a trace of mercury on his lip. Hayden's nose is bleeding silver. She says Liam can't tell anyone.

~~~

In the woods, Stiles and Lydia are going around in circles. They believe the Nemeton "doesn't want to be found." Lydia wants to go get Parrish to help them since he's the one who takes the bodies there. Stiles doesn't want to do that. He says because Lydia is a Banshee she should be able to find the bodies but Lydia says "The Banshee is having an off day."

He almost tells Lydia about Donovan but stops short.

Lydia leaves to go find Parrish and tell him that he's the one taking the bodies because "It's always better when they know."

~~~

Scott is having an asthma attack in the locker room. He takes a hit off his inhaler. As all the students leave he hears a single, elevated, heartbeat remaining. He rounds the corner to find Liam stuffing bottles of water and protein bars into a big red duffel bag.

Scott reminds him that it is a full moon, a supermoon, tomorrow and says Liam is probably already feeling the effects. Liam snaps at him and Scott backs off a little. He says he's there for Liam if he needs him and Liam snaps at him again, wondering if he plans to chain him to a tree again.

Scott says he just meant they should stick together so they can protect each other. Liam says "We can't protect anyone."

~~~

Stiles and Theo discuss the Nemeton in the school library. Stiles explains that Parrish dreams that he takes the bodies to the tree stump. Theo points out that if Lydia finds the Nemeton she'll also find Donovan. Stiles points out that she'll also find Josh. Theo says maybe they should come clean. He claims he believes Scott is different now and will understand they had no choice but to kill in self-defence.

Stiles imagines he sees himself impaled on a steel rod in the middle of the library.

~~~

Corey accidentally breaks the combination lock off his locker. Mason witnesses this and points out how much stronger he's getting. They decide to test his limits in the weight room by bench pressing more than 360 pounds.

Corey wonders if he might be the Dread Doctors "success." Mason says he doesn't know but Scott might. Corey doesn't want to be around Scott after the Alpha invaded his memories. Mason tries to convince him that Scott is trying to help.

~~~

A student named "S. Fitch" uses her student key card to access the library. The Sheriff slides in behind her before the door closes. He turns on his UV light and begins to sweep the floor. He finds a large stain of what appears to be mercury glowing. Small dark clouds evaporate off but are only visible under the special light.

He remembers what deputy Clark said about Theo Raeken and Stiles using their key cards on the night they got a prank 911 call from the library. He also remembers how suspicious Stiles was of Theo. The sheriff told him at the time that if someone is really guilty all you have to is wait because they'll eventually make a mistake.

~~~

In class, Theo says he needs to talk to Scott about something important about Stiles. He is interrupted when Scott hears ambulances approaching the school. They rush out to see Corey, covered in mercury blood, being loaded into an ambulance. The boy shouts "Don't let them kill me!" Mason stands nearby also covered in the mercury blood.

Theo urges Scott to do something and, after a moment's hesitation, Scott jumps into action.

~~~

Liam and Hayden meet up in the hall. She already knows the commotion must be Corey. Hayden says it means she's next. She and Liam run.

~~~

During the drive to the hospital, Theo makes up a lie about how Donovan died. He claims Stiles beat the boy's head to a bloodied pulp with a wrench, which Theo has in his glove compartment. He claims he got there too late to stop Stiles from killing the boy. He tells the truth about Donovan attacking Stiles and the wound on his shoulder (which Stiles lied about to Scott) but makes it sound like "self-defence" would just be an excuse Stiles would use for a wanton act of willful violence.

~~~

Natalie Martin is teaching about Anthrax and its use by Germany during World War I. Malia is distracted by the sound of someone chewing and notices a student named Beth chewing her fingernail. She has her laptop open and is looking at a graphic of the Perigee-syzygy. Mrs Martin tells her to close her computer and Beth complies but notices that the nail she's been chewing has come off and a trail of mercury blood is seeping from the ruined nail bed.

She runs out of class. Malia moves to follow but Martin blocks her way. The exchange the two have is about Malia's recent drop in grades but it becomes clear that Martin is aware of the supernatural. Malia realizes this and flashes her glowing eyes. Martin is unimpressed and says "I think you need to focus more on your school work, all of you."

~~~

Parrish and Lydia are driving through the preserve looking for the Nemeton. Parrish claims that he has no idea where he's going but makes a right turn as if he has a destination in mind.

~~~

Malia follows Beth into the hall and offers to help but the girl freaks out. She starts repeating the words "my condition" over and over. Malia steps closer and Beth throws her across the hall and into a locker. Malia, annoyed, gets up to follow again but as she rounds the corner of the hall she sees Beth is being held by The Pathologist. The doctor snaps the girl's neck as Malia watches.

~~~

The hospital is in chaos. Carts, a wheelchair and a gurney are overturned. The two paramedics that picked Corey up from the school are sitting on the floor being treated by a nurse. Scott realizes that the chimera must have escaped. He and Theo set out to find him.

Corey is standing, invisible, against the wall. He slowly becomes visible.

~~~

The bell rings at school, Stiles sees Malia. She is obviously upset by Beth's death. Malia says "I hate this. I hate losing like this. I'm not like Scott. I can't deal with another body, another failure," and walks off.

~~~

Scott and Theo have scoured the hospital looking for Corey but have had no luck. The power begins to fluctuate and they realize that the Dread Doctors have arrived.

~~~

In the ambulance bay, Corey too realizes that the doctors have come to claim him. He goes invisible once again, blending in with the side of an ambulance. The Surgeon walks slowly through the bay, draws his spike from his cane and stabs into invisible Corey. The boy becomes visible and slumps to the floor. The Surgeon walks away.

~~~

Scott and Theo discover Corey's body and decide they need to find Hayden.

~~~

Stiles is trying to get Lydia on the phone and leaves a voicemail explaining that there is another dead chimaera and that being around Parrish probably isn't safe. He repeatedly tells her not to get in his way if he's trying to retrieve the body.

~~~

Parrish and Lydia are wandering in the woods. Lydia decides he is thinking too hard about finding the Nemeton and that if he could stop thinking about it he could "feel" it. She decides that she will spar with the deputy to distract him. The trade a few blows and kicks. Lydia's skills have improved.

Suddenly, Parrish's eyes glow orange and, off to the side through a couple of trees, he sees the Nemeton. Several bodies are stacked around it.

~~~

At school, the Sheriff's department and Medical Examiner are dealing with Beth's body. The Sheriff singles out Theo and takes him to the locker room to question him about his library key card and the evidence he found.

Theo lies to the Sheriff and claims he killed Donovan and Stiles was not there. He relates events as they actually happened to Stiles, embellishing the story only a little by claiming Donovan wanted to kill Stiles in front of the Sheriff and that Theo bravely refused to tell the chimaera where he could find Stiles.

Theo works up real tears and does a plausible imitation of human emotions as he tells this lie. The sheriff seems to buy the whole thing and ends up hugging and comforting him. Theo's eyes change once the Sheriff can no longer see him.

~~~

Hayden breaks into the safe at Sinema. She tells Liam that the combination is 12/34/56 or 123456. Hayden says "Phil's an idiot." This is a reference to her boss, the bartender, Phil.

There are several envelopes in the safe. Hayden takes the one with her name written on it and opens it. There are two $100 bills inside. Hayden says her sister, Deputy Clark, is going to go out of her mind with worry. Liam says they'll come up with something to tell her. She wonders where they will go and Liam says "Wherever is far enough I guess." Hayden worries that she will turn out like Tracy and might hurt Liam. He says if that happens he'll "get over it."

The couple is kissing when the lights and projection system in the bar comes on. Old movies are projected on the walls and the lights for the dance floor spin and flash. They realize the Dread Doctors have arrived.

The Surgeon looks around the bar and breaks some bottles with his cane. Liam and Hayden make a run for the door but are blocked by the Pathologist who backhands Liam across the dance floor.

~~~

Parrish is completely freaked out. He says he needs to turn himself in for attacking fellow officers. He says he shouldn't even be near Lydia but she says she's not afraid of him. Lydia rationalizes the situation saying that, whatever is happening, it only seems to happen when there is a body and other than that he's still "a pretty nice guy and a pretty good deputy."

Parrish agrees saying he is a very good deputy and would like to stay that way but "Flipping over jeeps and attacking colleagues doesn't exactly fit with protect and serve."

He says he's covering up the bodies of murdered teenagers and this gets Lydia thinking that maybe Parrish is simply covering up evidence of the supernatural. She thinks maybe he is keeping the secret safe and that, somehow, this is his purpose. Lydia says he is more than a deputy and "you aren't one of the bad guys."

He tells her the rest of his dream about the Nemeton saying that, in the dream, there are hundreds of other bodies around the tree.

~~~

Liam is tossed into the wall at Sinema. He urges Hayden to run as the Pathologist approaches her. Scott roars and jumps into the fight. He punches, kicks and claws at the Pathologist with little effect.

Liam pounds on the Surgeon but the doctor hardly notices and tosses the boy across the floor again.

The werewolves attack both their targets again with similar results.

The Pathologist goes after Scott but he manages to dodge and escape. Scott renews his attack but the doctor head-butts him and knocks him into a pole. Scott goes down and the doctors turn their attention to Hayden.

Scott attacks again but is rebuffed. Theo shows up and tells Liam to get Hayden out. Theo takes on the Surgeon but to little effect.

Liam finds Hayden in another part of the bar. He is too late. The Geneticist has her and is injecting her with something. She falls to the floor as her eyes glaze over with mercury for a moment then clear.

Theo attacks the Surgeon again but once they get in close he says "I need more time." The doctor says, "The Perigee-syzygy. Until then." Scott is lying on the floor nearby but doesn't seem to understand what is being said.

Scott comes around and he and Theo go to find Hayden and Liam. Liam explains what happened. Scott decides to take her to the animal clinic.

~~~

Liam and Hayden ride in Theo's truck while Scott rides his motorcycle. Theo tells Liam not to let Hayden sleep. Liam tries to keep her awake while wondering aloud how they can help her. Theo says if it's Wolfsbane poisoning "you burn it out," but that he doesn't know anything about mercury. Liam wonders if she will heal but Theo points out that Hayden isn't a real werewolf. She is a "cheap knockoff."

Liam thinks if they turn her into a werewolf they can save her but Theo points out that neither of them have that ability. Liam realizes Scott can.

~~~

Parrish has locked himself in a cell at the Sheriff's station. Lydia tells the Sheriff that the deputy thinks he is protecting the rest of them.

The Sheriff is about to open the cell but Parrish stops him. He explains that he understands why the Sheriff sat him at a desk for six months. The sheriff says they can't keep him in jail but Parrish says there is another body. The sheriff admits that there are two. Parrish says he's been the one taking the bodies. He says he doesn't remember but that he is dangerous and needs to be locked up. The sheriff acquiesces.

~~~

Scott and Stiles arrive at the animal clinic at the same time. Stiles Jeep has been repaired enough to drive but he says he's still having trouble with the engine.

Scott doesn't know what to say to him after Theo's big lie. He removes the wrench from his coat pocket. Stiles wonders where he found it.

Scott says he knows about Donovan but doesn't give the details relayed to him by Theo.

Stiles, thinking his friend knows the actual story, doesn't provide details either. Theo's big lie stands between them.

Theo listens from inside the clinic.