Flush with new power as an alpha, Derek sets about building a pack. Technically, his first beta is Jackson Whittemore.
Derek finds Isaac Lahey in the Beacon Hills Cemetery the same night that something attacked Kate Argent's grave and overturned the backhoe that Isaac was using to dig another grave. Derek lifts the backhoe off the open grave and offers Isaac some help. He doesn't just mean with escaping the hole, though. Somehow Derek is aware that Isaac is abused.
The next morning, when Isaac is talking to the police about the grave robbing, Derek stands at the edge of the woods and watches. Isaac sees him, and then Derek disappears before anyone else can catch a glimpse of him. Later that day, he goes to the high school to check on Jackson. He finds Jackson in the bathroom bleed black blood everywhere. Derek realizes that Jackson's body is rejecting the bite and looks visibly disturbed. (Note: We later learn that he's seen this happen at least one other time when his high school girlfriend was bitten against her will by a visiting alpha and she asked him to end her suffering because of how painful it was.) He leaves without saying anything.
That night, Scott is chasing an omega through the woods. The omega hits a trip wire and gets caught, and Derek appears, hauling Scott behind a tree for safety as the hunters come out and inspect their catch. They cut the omega in half, and Derek forces Scott to watch so he will know what hunters really do. Derek tries to convince Scott that this is why he needs to be part of his pack for protection. Scott asks why the hunters just killed the omega and Derek replies that they're declaring war.
Derek then retreats to his new home, an abandoned subway tunnel. Isaac finds him there and accepts the bite.
The next day, Isaac's father is killed. Isaac knows it looks bad for him because they just had a fight and he goes to find Derek. Derek asks him what he did, but Isaac tells him that he didn't kill him. During school the following day, Derek shows up to get Scott. He observes Scott sniffing all the players on the lacrosse team to find out which one is a werewolf, but doesn't approach him. Later, Derek pulls up outside the school and tells Scott to get in the car. Scott doesn't want to go with him. He thinks Isaac needs a lawyer now that the police have arrested him for his dad's murder, not more "help" from Derek. Due to Scott's bad experience from being bitten by Peter, he thinks turning people into werewolves is immoral even if they choose it of their own free will. Derek insists that if Scott wants to help then he needs to get in the car because there's something at Isaac's house Scott needs to see.
They go to the Lahey's house and Derek tells Scott to use all his senses, not just smell. Scott realizes that Derek saw him on the field and Derek confirms that it did, indeed, look that bad. They head toward the basement and Derek directs Scott to go down and have a look. Scott asks what he's looking for and Derek replies it's motive. Scott eventually finds a freezer. He opens it and finds bloody scratch marks inside, implying that Isaac has been locked inside on many occasions.
Scott and Derek fight about Derek turning people. Derek insists that there's not a problem so long as there's informed consent, but Scott can't understand how anyone could really understand what they're agreeing to. Derek tells Scott that half his problems are because he's dating a hunter's daughter and Scott is surprised that Derek knows, given how little time they spend together. Derek tries to get Scott to join his pack, but Scott refuses because he'd lose Allison.
Scott needs to be locked up for that night's full moon, so Derek goes with Stiles to break Isaac out of jail. Stiles tells him that the keys are in his dad's office, but they'll need to get past the officer at the front desk. Derek says he'll distract her, but Stiles pulls him back saying he can't go in there. Derek glances between Stiles' hand on his shoulder and Stiles' face a couple times until Stiles takes his hand off; a display of Derek's issue of people touching him without permission, but handled lightly. Stiles takes his hand off and they have a playful back and forth over Derek being a person of interest and innocent. They make faces at each other while discussing how Derek intends to distract the deputy, Stiles asking if he's going to punch the deputy in the face and Derek saying he's going to talk to her. Stiles asks for a sample, essentially asking Derek to flirt with him. Derek responds with an attractive stare, implying that he intends to use his looks. Stiles assumes Derek isn't going to say anything to her and sarcastically remarks, "That should work beautifully. Any other ideas?" Derek rolls his eyes and jokingly responds that he's thinking about punching Stiles in the face, throwing Stiles' previous comment back at him.
Derek flirts with the officer at the front desk, although his stiffness and cheesy lines show he's not entirely comfortable with it. Over by the door, Stiles makes disbelieving faces before sneaking past to get Isaac.
Stiles pulls the fire alarm and Derek rushes back toward the holding cell to find that the fake police officer has already been taken down by a feral Isaac. The syringe of wolfsbane is on the floor and Derek crushes it. Isaac then turns on Stiles, but Derek gets between them and roars, flashing his red eyes. Isaac cowers away from him in fear and shifts back to a human. Stiles asks Derek how he did that and Derek looks over his shoulder at him to preen, "I'm the alpha." Stiles looks impressed and awed.
Derek takes Isaac and leaves before the Sheriff arrives with back-up.
Derek finds his next pack recruit in Erica Reyes. She's epileptic and ends up in the hospital after having a seizure on the rock wall at school. Derek wheels her into the morgue when no one is looking and uses his sex appeal to come onto her. He tells her that he can make her troubles go away, so she'll never have to suffer another seizure again. She agrees to the bite readily.
The next day, Erica is back at school, only now she's a bombshell, taking a page from Derek's book with a leather jacket and badass attitude. After she makes her entrance, presumably to show off to Scott, she heads outside and gets in the Camaro with Derek. He smiles at Scott and Stiles and drives off.
Derek's third beta is Vernon Boyd. He makes the offer to Boyd on the same day that Erica returns to school. The following day, Scott finds Boyd at work at the ice rink and tries to convince him not to take the bite, assuming Derek didn't fully inform them about the downsides to being a werewolf. Boyd reveals that Derek did in fact tell them about the negatives, including the threat of hunters, but he still chose to take the bite. Scott tells him that he can do a lot better than Derek for a friend, at which point Derek, Isaac, and Erica show up. Derek tells Scott he should take a poll to find out what people think of him and Isaac and Erica report that they're happy with their new powers. Given that Scott is the aggressor in this situation by trying to prevent people from making their own choices, Derek sends Isaac and Erica to attack Scott. Scott defeats them both, but Derek appears to have expected this and takes on Scott himself, defeating him handily. Having made his point that Scott shouldn't meddle with his pack's personal decisions, Derek leaves.
Given how poorly his betas performed against Scott, Derek starts giving them training sessions. They are in the subway tunnel hideout and Derek has them try to attack him. Isaac and Erica are very predictable, though, and Derek continues to grab them out of the air and throw them to the ground. He asks them to try something new, so Erica jumps up into his arms and kisses him. He kisses her back and then tosses her on the ground, telling her that's the last time she's going to do something like that. He has someone else in mind for her. He wants her to try to seduce Scott. Isaac complains about all his broken bones and Derek comes over and beaks his arm, the point being that as werewolves they are going to get hurt, but that they heal and can't stop to complain when they are under attack. He tells them that they need to learn everything he knows ASAP given the new threat that has appeared.
Somehow, Derek learns that Stiles had an encounter with the new reptile creature in town. He and his pack go to the high school. Erica finds Stiles breaking into the principal's office and drags him to the pool to talk to Derek. Derek asks what he saw at the mechanic's garage and Stiles makes a sarcastic quip about having seen several EPA violations. Although Derek is amused, he punctures a basketball in his hands - a throwback to his own high school days and courting Paige - and tells Stiles to try again. It is notable that this is the last time Derek uses intimidation to get Stiles to do something. Stiles gives him a cursory description and asks if he can go, but Derek gives him a look and he starts describing it in more detail. As he talks, the creature appears on a ledge above causing Derek and Erica to stare in horror. Stiles backs up next to Derek for safety and, when it attacks, Derek crouches defensively in front of him and roars at it. Derek turns to shove Stiles back while telling him to run, but in the process leaves an opening for the creature to give him a cut on the back of his neck, paralyzing him.
Stiles rushes forward to put Derek's arm around his neck and tries to help him get away to safety. Derek tells Stiles to call Scott, but Stiles fumbles the phone and loses his balance. Derek falls into the pool and Stiles jumps in to save him, knowing he won't be able to swim while paralyzed. They exchange a few sarcastic comments about being stuck in the pool while trying to see where the creature went. Aware of Derek's fear of drowning from being paralyzed while in the pool, Stiles complies with Derek's requests without much fight and tries to swim to the edge of the pool. Derek spots the creature and tells Stiles to stop.
Stiles spends the next two hours treading water, keeping them both breathing. They watch as the creature circles the pool and recoils when it touches the water. Stiles starts to get tired and looks at his phone on the ground by the pool. Derek knows he wants to go get it and tries to convince him not to. He believes that the only reason Stiles has been keeping him alive is because he's the only one that will be able to fight the creature once the paralysis wears off. Stiles is furious that Derek doesn't trust him and shoves him away from him to go for the phone. Stiles starts swimming toward the pool deck as Derek sinks to the bottom of the pool. After Scott hangs up on him without listening, Stiles throws his phone into the water and dives under the water to get Derek before he can drown. When Derek asks if Stiles was able to reach Scott, Stiles doesn't verbally respond but nuzzles Derek's head in a show of comfort. They're on their own for now.
Stiles can barely hold them up anymore and he starts swimming toward a diving board, which has a handle he might be able to hold on to. His strength fails and they both start to go under, but Scott appears and throws them both out of the water. Derek starts to recover some mobility and tries to pull himself up using the diving board as Scott fights with the creature. He watches as the creature runs from its own reflection and from this he's able to deduce that it's a kanima.
Derek and Erica meet with Scott and Stiles a little while later to share information. Derek explains to them that while they're both shapeshifters, werewolves and kanimas are different. Stiles supplies that it’s an “abomination,” simultaneously implying that he doesn't think Derek is a monster. Derek gets a raw, vulnerable look on his face as they lock gazes and share a moment. Scott tactlessly interrupts and argues that they all need to be working on this, including the Argents. At the mention of the hunters that murdered his family, Derek closes back up and makes the ultimatum that he’s going to find the kanima and kill it.
Now that he knows that they're after a kanima, Derek has two suspects as to who it could be: Jackson, who got the bite and rejected it, or Lydia, who got the bite from Peter but didn't turn. He sends Erica to find Jackson and bring him back to the subway hideout. Jackson is terrified of Derek and Derek does his best to intimidate him. He listens as Jackson claims he has a video of himself on the full moon that proves he didn't do anything, but then says that he's got his own method for finding out if Jackson's the one they're looking for. Derek puts on a pair of leather gloves and the pick up a piece of the mirror that Scott fought the kanima with. It has some venom still on it.
Erica and Isaac hold Jackson down and force his mouth open, and Derek puts a drop of venom on his tongue. Jackson loses motor function, much to Derek's disappointment. "You're still a snake, Jackson, just not the one we're looking for." They make Jackson recant his story about seeing Isaac fight with his dad so Isaac can stop being a fugitive.
Derek then sends Isaac and Erica to test Lydia. They plan to do it while they all have Chemistry class together. Derek waits outside with Boyd. Once Lydia has failed the test, Scott comes out to talk to him. He says he won't let Derek kill her and Derek replies that nobody said he was going to be the one to do it. Scott realizes that Isaac and Erica are going to do it, but Boyd won't let Scott leave. Derek asks Scott why he feels the need to protect everyone and points out that Lydia is dangerous and going to kill more people. Lydia was bitten by an alpha, if it wasn't Jackson, then it has to be her, because you can't be bitten by an alpha without somethinghappening to you. Scott argues that the kanima isn't like them, but Derek tells him that it is a shapeshifter and sometimes you take on a form that reflect the type of person you are. Scott argues that she's immune. Derek tells him that no one is immune. That's never happened. But if it didn't, then what about Jackson? Derek has no answer for that. Scott wildly accuses Derek of hoping that the bite would kill Jackson, although Derek's initial reaction to Jackson's bite not taking disproves this. Scott then suggests that Lydia passed her immunity on to him, which Derek isn't buying. Scott's not surprised that he couldn't convince him out of it and says that he had a back-up plan all along.
Lydia and her friends escape to Scott's house and Derek gathers his pack to follow. As night falls, they stand in front of Scott's house while everyone else barricades themselves inside. Derek sends Isaac in first, then Erica, while he stays outside with Boyd. It sounds like the fight is going well, until Scott opens the door and throws Isaac and Erica at Derek's feet. There are sirens in the background. Derek tells Scott that he understand why Scott keeps refusing to join his pack: because he's already the alpha of his own pack. But Scott also knows he can't take Derek in a fight. Scott tells him he doesn't have to, he just has to hold him off until the police arrive. Just then, the kanima crawls along the roof of Scott's house for everyone to see and Lydia runs out the front door demanding to know what's going on.
Derek tells Boyd to take Isaac and Erica home and then takes off after the kanima. He chases it to the warehouse district, where they fight. He keeps from getting hit with paralytic toxin this time, but the kanima rips out an electrical wire, causing sparks that momentarily blind Derek. The Argents arrive and start shooting the kanima and Derek escapes while they're occupied. He follows Scott and the kanima to the Jungle, the local gay bar.
Inside, both Scott and Derek attempt to find the kanima. Derek sees it first and manages to slash its throat. He disappears, thinking he's killed it. At some point, he learns that the kanima is still killing people, though, so the slash to the throat didn't work.
Derek explains to Erica and Isaac that the kanima is harder to kill than he thought, so he wants them to get close to Scott and Stiles, believing they know who it is. Isaac points out that the full moon is coming and Derek opens his trunk of chains to show that he's aware. Isaac is distressed that Derek will have to lock them up on the full moon, leaving him unprotected. He tells him that the Argents haven't found them yet, so they're reasonably safe. Isaac wants to give up the kanima hunt, but Derek tells him that he saw Gerard face the kanima without being afraid. He's not sure what that means, but he knows it isn't good.
The next time Derek sees Erica, Scott is carrying her back into the subway hideout while she's having a seizure. Stiles asks him if she's dying and Derek worriedly replies that she might, fearful of losing her. Stiles is outraged as Derek breaks Erica's arm, but Derek explains that he needed to trigger the healing process. He squeezes her arm hard to make her bleed in order to force the venom out. When it's clear she's going to live, Scott and Derek leave the subway car to talk. Scott says that he'll help Derek stop Jackson as part of his pack if he agrees to do things his way, which means no killing - not that slashing its throat worked anyway.
A few days later, Scott invites Derek to meet with Dr. Deaton. Derek brings Isaac along, much to Scott's annoyance, but Derek doesn't really care if they don't trust each other, they have bigger problems to worry about. Deaton asks if they plan to kill Jackson or save him. Derek replies, "Kill him," while Scott says, "Save him." Scott glares, and Derek relents. They go into the exam room, where Deaton has a tray of druidic ingredients. Isaac goes to touch one, but Derek grabs his hand to keep him from touching something dangerous. Deaton tells them that he doesn't have anything that could help with a paralytic toxin and Derek says they're open to suggestions.
He explains that he cut Jackson's throat pretty deeply and Chris Argent emptied a clip into it with no ill effects. Derek does say the kanima is afraid of water. Scott supplies that Jackson is the captain of the swim team. This gives Deaton the idea that maybe the kanima is feeding off of its master's fears. He suggests that they will be able to trap the kanima and the master together by using mountain ash.
Derek agrees to go along with this plan for capturing both the kanima and the master at the rave at the end of the week. Isaac and Erica will go into the rave with Scott. Derek and Boyd will stay outside while Stiles lays the mountain ash barrier. Things do not go exactly as planned when Chris Argent and his hunters show up.
Chris tells Derek to "Back off," and Derek smirks at him. He was expecting something little more dramatic from the big bad werewolf hunter. Chris replies with, "How about, didn't anyone ever tell you not to bring claws to a gun fight?" The hunters all take aim at Derek and Boyd. Boyd says that that one sounded pretty good and Derek gives him a look. They end up taking shelter behind a dumpster, waiting for an opening.
Once there's a break in the shooting, Derek and Boyd attack the hunters. Two of them hit Derek with tasers, but he grabs the cords and uses them to smash the hunters into each other, knocking them out. Boyd gets shot a few times and isn't healing. He and Derek hide behind a wall, and Derek tells him to take the car and get to safety. Boyd doesn't want to leave him but eventually listens and does anyway. Derek has to stay to find Scott.
He finds Stiles near the door to the rave. They stand closely together, clearly comfortable in each other's space, as Stiles tells him that they lost Jackson. Erica and Isaac come out, but they can't leave the building because of the mountain ash. Stiles realizes that the magic worked and looks at Derek, extremely proud of himself. Derek hears an agonized howl from Scott and orders Stiles to break the barrier. Stiles wants to know why and Derek can't believe he has to explain himself. He says Scott is dying and tells Stiles to break the barrier. Stiles does and Derek grips Stiles' shoulder in reassurance as he takes off to find Scott.
He bursts into the room where Victoria has been killing Scott with vaporized wolfsbane and is immediately staggered by the poison in the air. Victoria stabs him in the back and Derek turns to fight with her. They scuffle and during the struggle Derek bites her shoulder. She runs away and Derek grabs Scott and hauls him out of the room. He takes him directly to the Animal Clinic. Scott is unconscious for a while. Derek sits in the corner and watches. He thanks Deaton for his help.
Later that night, Derek and Scott return to the subway hideout to talk about their options. Derek doesn't know what to do. Scott's finally accepted that they can't save Jackson, but Derek points out that they can't seem to kill him either. Scott suggests letting the Argents handle it, but Derek feels responsible because he's the one that bit Jackson. Scott points out that he didn't turn him into a kanima, something in his past did. Derek says it isn't that simple but won't elaborate, which makes Scott think he's hiding something again. Scott complains that being part of Derek's pack should mean no more secrets - while at the same time keeping secrets from Derek. Derek doesn't tell him anything else and instead tells him to get ready for the full moon, because it's going to be a bad one.
On the Worm Moon, Derek opens the trunk of chains so he can start chaining his betas up. Isaac asks what the symbol on the trunk means and Boyd offers that it's a triskele, which can mean a lot of things. Derek asks him if he knows what it means to him and Boyd suggests alpha, beta, omega. Derek is impressed and elaborates that it means that a werewolf can rise or fall to any status. Isaac asks about Scott being an omega, but Derek defends him, claiming that he's part of their pack now. Isaac isn't buying it because Scott isn't there with the rest of them.
Derek explains that the price they pay for their power is bloodlust on the full moon. Erica quips about it being a good thing she had her period last week, and Derek smiles a little at her. He holds up a headband that she will have to wear.
That evening, Derek bolts them all into the subway car, starting with Erica. He explains that she can withstand more pain than the boys, which is why she gets the headband bolted to her skull. He asks if she's ready and then starts turning the screws of the band. Erica screams.
As he's chaining Isaac up, Isaac asks him whether he feels the full moon like they do. Derek tells him that he feels every second of it but he keeps his human side in control by focusing on his anchor. For him, his anchor is anger, but it can be different for everyone. Derek finishes with the chains, and Isaac tests them. He pulls the foot of the seat he's chained to out of the floor.
Derek calls Scott and asks him to call him back right away because he thinks he's going to need some help. Scott doesn't return his call.
As the betas start to roar and scream, Derek flicks out his claws and goes back into the car. Erica attacks him first. As he's fighting her, Boyd breaks free, then Isaac. Isaac leaps out the window and disappears. Derek manages to fight off Erica and Boyd for a while. He gets Erica back to where he can chain her up, and then Isaac returns and holds back Boyd. Derek turns to look at him and they nod at one another in recognition.
Even though Isaac has control now, Derek still chains him back up. He asks Isaac what he found as an anchor and Isaac tells him it's his father. Derek's surprised. "Your father locked you in a freezer in the basement to punish you." "He didn't used to."
After Isaac is chained up, Derek leaves the subway car to find Lydia standing there. He stares at her in confusion and she blows purple powder into his face. It knocks him out, and she drags him away. Somehow, Lydia gets Derek from the subway hideout to the Hale House. He starts coming around as she drags him across the floor boards. Derek begs her to stop, but he doesn't have the strength to move on his own. She places his arm into Peter's dead hand. Lydia redirects the moon light so it shines directly onto Peter and then Peter's claws dig into Derek's arm. Derek's alpha blood brings Peter back to life.
Derek drifts in a white place, possibly the same one Stiles, Scott, and Allison enter in 3x12 - Lunar Ellipse, although no details of the space can be seen. Someone is calling his name, but it sounds fuzzy. "We don't have much time," the voice says, and then Derek hears a piercing sound that brings him back to his body. Dr. Deaton is kneeling over him. Derek asks what the sound was and Deaton holds up a dog whistle, grinning. Derek smirks and tries to stand, but he stumbles. Deaton catches him and tells him that he's going to be weak for a few hours. Derek flashes back to Peter coming back to life and realizes it wasn't a dream. Deaton tells him that he's still an alpha, "but, as usual, not a particularly competent one" - a rather cheap shot considering how little help and advice he's given Derek, especially given Derek's lack of any sort of support network since his family died. Derek lets the insult go and asks where Peter is. Deaton doesn't know. Derek demands to know why Deaton is helping him. "Helping your family actually used to be a pretty important part of my life. Helping you was a promise I made to your mother." Derek backs off and says that Laura told him there was a sort of advisor to their family.
Deaton says that Peter's resurrection comes with a price. He will be physically weak, so he will rely on his intelligence and cunning. "He's going to come at you, Derek. He'll try to twist his way inside your head, preying on your insecurities. He'll tell you he's the only way you can stop Gerard. Do not trust him." Derek replies that he doesn't trust anyone. Deaton replies that if he did he might be the alpha he likes to think he is. "Unfortunately, the one person you should trust doesn't trust you at all." "Scott." Deaton tells him to find Scott as fast as he can because Gerard always has a plan and it's so far going exactly how he wants. Derek spends most of the conversation looking worried, even while Deaton is insulting him. Deaton's comments about trust are particularly egregious given that he and Scott are going behind Derek's back and using him to defeat Gerard.
Derek tracks Scott down to the sheriff's station, but gets caught by the kanima. When Scott opens the door to the station thinking that his mom has arrived, Jackson tosses Derek onto the floor. Scott stares down at Derek while Matt leans over him. "This is the one controlling him? This kid?" Derek asks. "Well Derek, not everyone's lucky enough to be a big bad werewolf," Matt replies. Matt has learned about werewolves, hunters, and kanimas. It's like Halloween every full moon. "Except for you Stiles. What do you turn into?" "Abominable Snowman, but it's more of like a winter time thing. You know, seasonal." Matt has Jackson paralyze Stiles, and Stiles falls on top of Derek. Derek grumbles for someone to get Stiles off of him, but Matt thinks they make a good pair. He taunts Derek about how strange it must be for him to feel so helpless. "Still got some teeth. Why don't get down here a little, huh, we'll see how helpless I am," Derek says. "Yeah, bitch," Stiles adds.
When Scott's mom arrives for real, Matt has Jackson move Derek and Stiles to another room. Matt tells Scott that he needs the bestiary. Scott tells him that Gerard is the one who has it. Matt claims he needs answers. "Answers to what?" Matt lifts up his shirt and shows them his skin, which is turning into the kanima's hide. Stiles and Derek on the floor both look shocked.
Stiles asks Derek if he knows what's happening to Matt. Derek replies that the book isn't going to help him. He can't just break the rules like he has been. The universe will balance things out. Because Matt's been using the kanima to kill people who don't deserve it and killing people himself, he's turning into a kanima. "Will he believe us if we tell him that?" Stiles asks. "Not likely." Stiles asks if Matt's going to kill them all when he gets the book. Derek says yes. Stiles asks if they just sit there and wait to die. "Unless I can figure out a way to push the toxin out of my system faster. Like triggering the healing process." Stiles glances down and sees Derek digging his claws into his own leg.
A little while later Stiles asks Derek if his hypothetical healing is getting any less hypothetical. Derek says he thinks so because he can move his toes. Stiles sighs and tells him that he can move his toes, too. Suddenly, all the lights go out. The Argents have arrived thanks to Matt's text demanding the bestiary in which he mentioned Derek, and they open fire with automatic weapons.
Derek eventually regains his mobility and tracks down the kanima in lock-up. Melissa McCall is in the cell and can see him and the kanima clearly. Derek and the kanima fight, while Melissa watches. Derek tries to keep the kanima away using a chair, but the kanima throws him hard into a wall. Then it crawls on the bars in front of Melissa.
Scott runs into Gerard in the hallway and says that it wasn't supposed to happen like this. He's done everything that Gerard has asked him to do. "I'm part of Derek's pack. I've given you all the information that you wanted. I told you Matt was controlling Jackson." Gerard tells Scott to leave Jackson to them. Derek overhears their conversation and knows he's been betrayed.
Not long after, Derek is in the Hale House looking through old books. Boyd and Erica find him there and tell him that they've decided to leave. Erica says that she only turned 16 a month ago and would like to get her driver's license. Derek replies that he told them there would be a price. Boyd says that they didn't know it would be this dangerous. Derek says that they need to be in a pack to survive, and Boyd tells him that they know. That's when Derek realizes that they want to look for another pack. He asks them how they're going to find one. Boyd thinks they already did, which catches Derek off guard.
Boyd and Erica tell Derek about the howling that they heard. Derek explains the Beau Geste effect, where wolves can modulate their howls so that two can sound like twenty. Boyd and Erica are unswayed. They say they're leaving, but Derek says they're running. "Once you start, you don't stop. You'll always be running." It's another one of his speeches from experience. Erica takes Boyd by the hand and pulls him away.
Derek turns away to glower, then picks up a shard of broken mirror and throws it like a knife. Peter catches it just as it's about to cut his throat. "I expected a slightly warmer welcome," he says.
Derek asks Peter what he wants, and Peter just claims he wants to help his favorite nephew. He asks Derek if they can just talk and puts his hand on Derek's shoulder. Derek throws him across the room into the staircase.
Derek continues to toss Peter around the house and beat him up. Peter kind of laughs and assures him that he doesn't want to be the alpha again considering that his last attempt at it ended in his death. Derek grabs him to punch him again, and Peter tells him to bring it on, to get out all the anger and self-loathing that comes with total and complete failure. "I may be the one taking the beating, Derek, but you've already been beaten. So go ahead. Hit me if it will make you feel better." Derek stops hitting him and shoves him away.
Peter gives Derek a rundown of his failures. Derek glares at him. "How about you tell me something I don't know." Peter promises to tell him how to stop Jackson. Specifically, how to save him. Peter explains that there's a myth that you can cure a Werewolf by calling out its Christian name. This is stupid of course, but sometimes myths bear a hint of truth. "Our names are a symbol of who we are. The kanima has no identity. That's why it doesn't seek a pack." Peter says that they need to bring Jackson's identity back to him. "How?" "Through his heart! How else?" Derek says that Jackson doesn't have too much of a heart to begin with, but Peter doesn't believe that. He says there's one person that Jackson shared a real bond with, who can reach him: Lydia.
Peter tells Derek that he relies too much on anger and needs more heart, which is why he's always known that he needs Scott.
Derek agrees to try Peter's plan, and they go to find Scott at the high school. Scott is stunned to see Peter alive. Derek responds that he felt similarly when he heard Scott talking with Gerard. Scott defends his actions, telling him that Gerard threatened to kill his mom. Peter sides with Scott, since his mom is gorgeous. "Shut up," Derek and Scott both say. Derek explains that Peter can help them save Jackson, but Isaac replies that Jackson is dead. Scott tells them it just happened on the lacrosse field. Everyone looks concerned, and Peter says that if Jackson is dead it's because Gerard wanted him to be, so they need to figure out what his plan is very quickly.
Scott, Isaac, Derek, and Peter go to the Hale House. Derek protests that he looked everywhere, but Peter goes straight for a loose board in the main staircase. "You didn't look here." He pulls out on a briefcase covered in dust. "What is that, a book?" Derek asks. Peter gives him a scathing look, because it's a laptop. Scott gets a call from his mom that something is wrong with Jackson's body, so he and Isaac go while Derek and Peter stay.
Derek's on the phone with Scott and reports to Peter that Jackson is encased in a cocoon of kanima venom. Peter finds information on the alpha form form of a kanima and shows Derek. Derek is incredulous because it has wings. Peter finds an animation of the new form and plays it. Both he and Derek jump in terror and slam the laptop closed. Derek tells Scott and Isaac to get Jackson and meet them halfway.
Derek gallops up the street toward Chris, Scott, and Isaac on all fours and does a forward flip, landing in a crouch with his red eyes glowing. Derek stares at the unexpected Chris, and Chris announces that he's only there for Jackson. Derek is not comforted. They take Jackson inside a warehouse, and Scott asks where Peter and Lydia are. Scott realizes that Derek isn't going to try to save Jackson, and Derek tells him to wisen up, that Gerard is controlling Jackson and has been planning to make Jackson even more powerful.
Gerard appears, confirming their suspicious, and Derek tries to kill Jackson, but Jackson shoves his claws into Derek's chest and throws him across the warehouse. Derek, despite having been impaled on the kanima's claws, is not paralyzed and comes flying over some pallets with a roar. Scott and Isaac rush to join him, while Peter watches from a safe distance. The kanima's claws don't have any noticeable paralytic effect until it swipes Derek across the middle. Allison starts to go for Derek, but Scott steps in the way.
Gerard reveals his plan to become a werewolf to keep from dying of cancer. Derek looks up at him helplessly. Scott hauls Derek up, and Derek begs him not to do this because Gerard will kill him immediately after and become an alpha. Derek begs some more, and Scott says that he's sorry but he has to. He jerks Derek back so his mouth is open, and Gerard impales himself on Derek's teeth, essentially using Derek's body against his consent to give himself the bite.
Derek gives Scott a wounded look. "Why didn't you tell me?" "Because you might be an alpha, but you're not mine."
Derek is recovering from the paralysis, and he sees Peter making his move while Jackson is distracted with the newly arrived Lydia. Derek's eyes go red, and he joins him. They both stab Jackson with their claws from either side. Lydia rushes forward and catches Jackson in her arms as he falls. Derek backs away and pulls Isaac by the shoulder back with him.
After the showdown with Gerard, Derek, Isaac, and Peter wander up to the Hale House, and Peter announces that Derek hasn't told Isaac everything. Isaac asks what the symbol on the door of the house means, and Derek tells him that it means the alpha pack is coming.