The Beast jumps in the middle of a road at night, police sirens can be heard in the near distance. Multiple police vehicles are speeding down the road, Stiles and Scott happen to be close behind. Then a series of calls over the radio occur. Dpt. Clark describes seeing a "incredibly large something" headed northwest on Crescent, she makes sure to specify that this isn't a animal. Deputy Strauss calls in a 1091-E (Animal Attack) from down town, apparently there are multiple fatalities. Stiles gets on the radio in his Jeep and tells all officers to stay back at Sheriff Stilinski yells at him to get off of the radio.
He and Scott then realize that the beast is headed towards the hospital and they warn everyone. Right after this, they receive another call of a man on fire headed towards Beacon Hills Memorial Hospital. Scott and Stiles arrive at the hospital with the sheriff right behind. They hear loud growls coming from above, Scott says its on the 4th floor, they find a very smokey and charred hallway, certain areas were even still on fire. As they turn the corner, Hellhound, Parrish who is completely on fire is throw down the hall into the wall. Parrish’s flames burn out but he appears to be dazed, the Sheriff yells his name and he wakes up.
Scott follows the beast bloody foot prints down the hall he notices that in between steps, the beast foot prints turn from a huge monstrous paw print into a shoe print. At the animal clinic, Deaton has a file in hand that he says shouldn't exist. The files contains pictures and extensive records of experimentation performed on the supernatural creatures of Beacon Hills by Gabriel Valack, he conducted these experiments during his time as Chief of Medicine at Eichen House. The photos depict a series of dead supernatural creatures like werewolves, banshees, wendiogs and much more, pretty much anything he could get his hands on. Valack discovered that trepanation would heighten a subject’s powers and abilities but such high levels couldn’t be contained.
Scott realizes that Valack wishes to make Lydia more powerful, Deaton replies that Lydia's powers were already exceptional as they were and a whole in her head is like a leak in a nuclear reactor. With her enhanced abilities, she would be able to hear every dying scream all at once and this would kill her but not only that, her own dying scream would be so powerful it might kill everyone around her. At the Sheriff's station, Stilinski tells Stiles he's doing everything he can to get Lydia out but it's really not up to him, it comes down to Natalie Martin. Stiles wants him to get a court order but the sheriff explains that trepanation is still considered by many a medical procedure and a court order would take months to get and the judge probably wouldn't grant it. The sheriff goes on to say that there is nothing they can do "legally."
At the McCall House, Stiles and Scott explain their plan to break Lydia out of Eichen. This will require them to get past the guard/orderlies, electronic locked doors and the Mountain Ash barriers. The plan involves Kira stealing power from the main system and causing a brownout so the electronic locks will reboot and reset in order for the badge that Stiles stole to work. During the time of the reboot, alarms will turn off, after that, Scott and Liam will get Stiles to the gate of the closed unit, since they can't get past the Mountain Ash barrier, if will be up to Stiles to retrieve Lydia. If the plan goes well, everyone will think it was just another reboot caused by a brownout. However, the pack is doubtful of the plan but Scott reminds them that they have to do this or a lot of people will die.
At Eichen, Valack and nurse Cross walk down an old Eichen House hallway, Valack retrieves what appears to be a mask from one of the Dread Doctors out of a storage locker, however, it is badly damaged, the mask hasn't been used in years. When nurse Cross turns away, Valack forces the mask on to her head. She begins screaming and breathing heavily for a few moments before falling down on the floor then her eye opens up through one of the holes. Malia and Kira are in the biology lab at school at Beacon Hills High School, Kira is practicing using her electric abilities. She's reluctant in completely the task due to lack in confidence. Malia asks how she learned to use her powers and the sword, Kira admits that she didn't need to learn, it happened naturally, Malia then calls her a cheater.
Kira grabs the device but instead of taking power it, she sends more power in and explodes the lightbulb, a shard of glass from the broken bulb is stuck in Malia’s head. She pulls it out and give Kira new lightbulb saying try again. Melissa McCall is at the hospital with Scott and Liam, she retrieves body bags from the hospital morgue. Liam points out that they still have no idea who the beast is, if it's possibly someone they know or even if he knows what he's doing, Melissa points out that it might not be a he. Melissa is becoming aggressive with Liam and he along with Scott notices. Melissa explains that she's not mad but if he ever tries to kill her son again she’ll put him in one of the bags herself.
Stiles attempts to convince Parrish to drive the Sheriff’s vehicle to Eichen House. Parrish says it's not safe to be around him because he’s dangerous. Stiles points out that the beast who has killed dozens of people somehow couldn't kill Parrish. The biology lab at the school is covered in broken lightbulbs. Malia has acquired goggles and is sitting a few feet away from. Kira then asks about the Desert Wolf and her failed attempt to kill Malia, she quickly changes the subject back to Kira’s time with the skinwalkers and practicing with electricity. Malia takes off the goggles and steps closer, assuring Kira that she trusts her, Malia knows Kira will get it right because it's the only way to rescue Lydia. Kira grabs the device and the bulb dims almost completely but Kira loses control, the bulb lights up and breaks. The entire power grid of the school goes out, they both run out. After the exit,Corey makes himself visible, he has been their spying on them.
In the library, Scott and Stiles are talking about the show print that the beast left. Stiles explains that it should be physically possible for a person to just go from animal like paw prints to sneaker. Scott reminds him that Argent said it would be unlike anything they have ever seen before. Theo is also in the library, listening to their conversation. Stiles wants makes it known that he wants to kick Theo's ass, Theo admits that mistakes were made but Stiles points out that murders were made. He tells Scott that he and his pack can help them get past the Mountain Ash at Eichen House and save Lyida. Scott wonders what his motives are, Theo says the fresco in the Dread Doctor's lair is his motive. He just wants to stay alive and not be in the pile of bodies when the "two seriously pissed off creatures, the Hellhound and the beast", end up fighting. Theo says he can get them to Lydia or they can see who gets their first. After Theo leaves, they wonder what he could want with Lydia.
The sheriff tries to convince Natalie Martin to take Lydia out of Eichen House, he says she knows what's going on in this town, the closed unit at Eichen house and what goes on down there. She then tells the sheriff the story of her mother-in-law Lorraine Martin and how she predicted the death of her wife. Natalie then says that she also had similar experience once when she was in college, she had a feeling her sister was in trouble and later called and found out that her appendix had burst. The Sheriff tells her about the supernatural occurrences that happen but she brushes them off as coincidences. Before Stilinski leaves, he drops the file on Valack’s experiments on her desk says it just might expand her definition of the word coincidence.
Back at Scott's house, Kira tries to convince everyone that she can't do this but they all believe in her with the exception of Malia, after being pressed by Stiles, Malia also offers words of encouragement. AT Eichen, she and Kira appear to be on a tour, they're with a large group, as soon as the enter, they hide in a corner. Parrish drives the sheriff's van up to the guards station and tells him that he's there to deliver the bodies to the morgue. The guards is unsure of him, so he makes Parrish get out and check the bags, Parrish opens the body bag and a badly damaged body is shown. The guard nearly pukes, he then tells Parrish to go on through. Malia is waiting for her "guy" to come in, so that her and Kira can get into the back. At that moment, a naked guy named Nelson comes out and the orderlies leave their post which includes the reception which is right on front of the electrical room to apprehend Nelson.
Scott, Stiles, and Liam are in the morgue, they unzip the bags and Scott says it is 7:45 PM and they have 15 minutes. After the guards outside pass the door, they come out. Kira and Malia have found the electrical box but the wires are covered in rubber, so Malia grabs a pair of scissors to cut it of but Kira knows it can kill her, so instead of using the the scissors, against Kira's advice, Malia uses her claws, there's a spark and Malia's hands are blackened and smokey but she is okay and the rubber is off. Four minutes until Kira has to cause the brownout and Scott, Liam and Stiles are stuck hiding behind a wall because the guards are blocking the door, Liam wants to take them but its not a good idea. A patients begins to bang on the glass, asking for Conrad Fenris, he won't shut up and he's attracting the guards, so Scott shows his eyes and fangs which get the guy to shut up and then the orderlies leave.
Kira is scared she’ll lose control and fry the entire system, so she's not doing anything. Malia attempts to encourage her by telling her to stop worrying and focus on saving Lydia and getting her out. Kira begins draining the power, lightning begins to spark around the wires and around Kira's hands, then the computers reboots. The boys get to the final gate only to find that the key card lock is removed. Scott and Liam try to break the gate but cannot due to the mountain ash.
Theo and his pack invade Eichen House, they reach the reception and make their way to the closed ward. In the dread doctors lab, Hayden is watching Deucalion, he tries to convince her to let him go free. He gives her a few details on Belasko's talons, Deucalion tells her that Theo plans to attach the claws to his own like some press-on nails and use them to steal the power from the beast will fail. He says the plan won't work due to the fact that the talons were created by the Dread Doctors with their own frequency specifically for Belasko. If Theo puts on the talons, it will kill him.
Liam and Scott are still at the door but are both too weak to push it open, Liam tells Scott to punch him, doing this will cause Liam to get angry and it will make him stronger. Scott is initially reluctant to punch his own beta but he eventually does, several times until Liam gets mad. Once enraged, his eyes begin to glow then he and Scott use all their power to force the door down, now it is up to Stiles to get Lydia out. He goes running down the hall into Lydia's room where he finds her strapped to the bed and blood flowing out the hole in her head. He tries to free her but Lydia tells him to go because if he doesn't he will die. Malia and Kira open the door into the office to find a couple of guards standing in the lobby. They decide its better to stay back to avoid raising the alarm until Lydia is out.
Valack comes walking down the hall and Lydia begs him to go before Valack sees him, Stiles leaves and hides behind a wall, listening in on Valack and Lydia's conversation. Outside in the van, Parrish's eyes begin to glow. Natalie Martin arrives at Eichen only to find a dead guard lying on the ground. Kira and Malia enter the lobby to see one of the orderlies have been knocked out and then Kira's powers start acting weird just like the last time she was their, Malia decides that they need to go and meet up with the rest of the pack at the morgue. Valack is questioning Lydia, he tells he has amplified her abilities and it might just save her friends. Lydia tells him that Theo and Hayden found Scott’s symbol carved into a wall, Valack knows that its a promise to reunite the pack. He wants to know if they will come for her next, Lydia says someone is coming but it's not Scott, he looks out the room and sees Theo and his pack coming that way.
Time is up to get Lydia out but Stiles hasn't returned, so Liam and Scott are attempting to get through the ash but they can't, Liam reminds Scott that he did it before but that was under life or death circumstances, Liam says this is one of those situation, however, Scott still isn't healed. Then four guards attack them with lightning rods. Valack is being held against the wall by Tracy, he's curious as to why a pack of chimeras would want a banshee, Theo replies that he doesn't want a banshee, he wants a hellhound. Immediately after saying this, hellhound Parrish is at the door flaming with claws and fangs, he melts the door down and begins walking towards Theo and his pack. Malial and Kira enter the morgue to see taht no one is there, then sirens begin to go off, they try to open one of the doors but Malia is shocked and is sent flying back into Kira.
In the front of the building just as Natalie was about to enter, steal doors come slamming down thus putting Eichen on lock down. Scott and Liam are being destroyed by the guards, the tazers are just too much until Scott notices Liam is really hurt and he roars, it echos through out Eichen and Stiles, Kira and Malia hear it, her eyes even glowed. Scott then take out the guards.