Kira wakes up in the same bone-filled cell where we last saw her. Now though, the cell door is open. As she makes her way down the dirty stone corridor she notes a Berserker standing guard at the other end. Turning to retreat, another Berserker attacks her. She notices the double bands of black tattoo on his arm and knows that the Berserker is Scott. She tries to talk to him but he continues to beat her mercilessly until Kate calls him off.

Kate explains that after escaping the Calaveras she didn't know where to go but kept feeling a pull from Tezcatlipoca. She explains that his name means "smoking mirror" and the temple under La Iglesia was known as "the temple of the smoking mirror."

(The Aztec deity known as Tezcatlipoca was often depicted with body parts made of obsidian. He was always connected to this particular volcanic rock from which mirrors were made. Many times the god was shown with a chest plate of obsidian from which smoke would issue.)

Kate points out that the temple is partially made of obsidian. Kate says the Berserkers were waiting for her when she arrived at the temple and helped her survive. She says she didn't know why they were helping her until recently when someone with whom she was working explained it to her. She learned from this unnamed ally that she could control the berserkers and make new berserkers. Kate says they call her La Loba, The Bone Woman. She says they let Kira out to test Scott's loyalty as a Berserker. She complains that Scott's never had to kill anyone despite all he's been through. She thinks it's time to change that.

(I don't know if I should mention it but La Loba means The Wolf. The right translation in Spanish is more something like La Mujer de Hueso)

Scott takes out a dagger of bone and stabs Kira.

~~~

Sheriff Stilinski forbids Stiles to go after Scott and Kira in Mexico. The sheriff wants to call law enforcement in Mexico to help. Stiles says there is no time and declares that he is going. The sheriff threatens to lock Stiles up but his son says he will still find a way to go. He asks Stiles for more time saying he will do all he can through channels and if it doesn't work he and Stiles will both go to Mexico.

~~~

In the loft with a table full of guns, Derek feels helpless. Braeden points out that she is human and she's not helpless. Derek confesses he doesn't expect to live through rescuing Scott. Braeden says she's not okay with that and they kiss. Derek says if he can save Scott and Kira he's willing to die.

Peter comes down the spiral stairs and says they don't have near enough firepower to take down even one berserker. He says defeating them isn't just about firepower; they have to break the animal spirit from the human inside. Derek says only Argent has real experience and he's "not getting back to me." Peter suggests they're going to need help he says "like Malia, maybe Liam, definitely me."

~~~

Stiles is going through Scott's closet looking for something for Malia to sniff so she can track Scott. His shirts smell like fabric softener so Stiles looks in the dirty clothes hamper in the bathroom and comes up with a pair of boxers. Stiles makes a face and Reed rolls his eyes. He throws a pillow at Stiles and another at Malia.

"That works too," Stiles says

Liam is downstairs and Stiles tells him to go home. Due to Liam's lack of control during the full moon, he will be a liability on the trip. Stiles says considering how he tore through chains during his last full moon they would have to "freeze him in carbonite" to get him to Mexico. Liam says that's great and asks "where do we get carbonite?" Liam insists that he wants to help save Scott and they decide they will have to come up with some special way to restrain him after Reed points out that if they're all going to Mexico and leave Liam here, he might kill someone.

~~~

Braeden, in her guise as a US Marshal, "borrows" a prisoner transport van to help secure Liam. Derek is surprised that Stiles is bringing Liam. Stiles is surprised that Derek is bringing Peter. Peter says they should get moving since it's about to be a full moon and Kate may try the same "age regression" trick she pulled on Derek with Scott. Peter says a werewolf can't steal a True Alpha's power but maybe Kate would be able to with the power of the temple.

Peter wants to leave but Stiles says they need to wait on Lydia and Cheryl. They're at the school getting something of Kira's to help them track her scent.

~~~

Lydia finds a jacket in Kira's locker and turns to give Cheryl a triumphal smile but is attacked by a Berserker.

~~~

Stiles keeps calling Lydia but can't get her, Liz has the same problem with Cheryl. Braeden suggests they can catch up with them on the road. Stiles, Liz and Reed don't want to leave them but Liam suggests they call Mason, who is already at school for a study break, to see if he can find Lydia.

Stiles says he'll ride with Derek and Liam since he has experience dealing with "out of control teen wolves" and asks Malia if she will be okay riding with Peter. She says "he is my father, maybe we can do some bonding." Stiles says no bonding and insists that she "play the radio and play it loud."

Liz is also driving with Derek, Liam and Stiles while Reed is driving with Peter and Malia.

Peter encourages all of them to remember that they "might see human eyes behind those skulls" but not to "assume there is any humanity left." He then senses that Liam is terrified of berserkers and says his fear will keep him alive. He reminds them all, "you do not fight berserkers to survive - you fight to kill."

~~~

Mason finds Lydia's car in the school parking lot while on the phone with Liam. He says he'll continue to look around the school to see if he can find her and Cheryl. Liam says to call as soon as he does.

~~~

The Pack caravans through the desert, Peter drives first in his SUV followed closely by Braeden in the prisoner transport. In the back of the van, Derek attaches handcuffs and chains to Liam. He strains against them and they seem to hold him secure to the metal bench. Derek then brings out the triskelion disk his family used to teach betas control on the full moon.

"Okay. Now, I brought something to help you. This has been with my family for centuries-- it's a very powerful supernatural talisman. We use it to teach Betas how to control themselves on a full moon" Derek explains and both Liz and Stiles then both give him the same look because they know none of that is true but Derek, also with a look, admonishes them to keep quiet. Stiles then reinforces what Derek has said "very powerful."

~~~

Mason searches for Lydia. He finds Kira's jacket and Lydia's phone on the stairs and as he activates the screen a picture of a berserker skull appears. A shadow falls over Mason as a berserker blocks his path.

~~~

On the road, Malia has the radio up loud. Peter asks if he can turn it down and she agrees. He asks if she's worried about Stiles and she says she's worried about everyone. Peter asks if he needs to be worried about Malia. He says they have to go through the berserkers to get to Kate and then through Kate to get to Kira and Scott and that it will be "messy." Malia says Scott told her that "we don't kill people." Peter turns it around asking if Scott would kill to save Kira or if Malia would kill to save Stiles. She doesn't answer, just looks out the window at the full moon. Peter says she'll need that power.

~~~

Braeden takes her eyes off the road to look through the metal grate into the back of the van. Liam is beginning to lose it. Warning all of them to start teaching him what needs to be taught.

~~~

Kira is badly wounded. She sees her mother. Kira says she's not healing because she never learned how. Noshiko explains that foxes and wolves have a number of things in common including healing and asks Kira how the wolves start healing when it doesn't come automatically. Kira remembers it is pain that triggers it. She begins to pound on the obsidian rock near her, breaking off a piece and squeezing the sharp rock in her hand until she begins to bleed. Her eyes glow fiery orange of a Kitsune.

~~~

Mason wakes up in the basement of the school with Lydia and Cheryl. He describes "this guy" who had a skull over his face. Mason's phone is gone and Cheryl says that's the point to keep them from getting out or contacting anyone.

~~~

Derek is trying to calm Liam. He explains what each spiral of the triskelion means to his family - Alpha, Beta, and Omega. He says, just like the tattoo on his back, it reminds him that Betas can rise to Alpha, Alphas can fall to Betas. Liam asks if Alphas can become Omegas and Derek says they can. He explains that Liam must use the three status names as a mantra and each time he says it he is becoming more in control. Liam tries the mantra but it doesn't work.

"Hey! Hey, Liam! Look at me" Liz says and Liam's head snaps in her direction. He growls at her and she lets her eyes glow. "Look at me, I'm like you okay. We all needed to learn control. Now tries to focus on something anything. Okay? Now what three things can not long stay hidden?" Liz asks.

"The sun... The moon... the truth" Liam repeats it a few times and eventually calms down.

"You're a witch, you didn't need to learn control" Derek then points out.

"I did, I mean I'm technically still learning but still. If Selene hadn't used the mantra to calm me down then... I would've burned my whole school down" Liz admits and looks away. Liam puts his hand on hers and Liz smiles at him softly.

~~~

Malia is struggling too. Peter notices. She says she's trying to stay human. He says that's a problem because "Scott and Selene have you thinking that control and humanity are the same for us." He offers her some "fatherly advice" saying that facing something as animal as a berserker will require that she focus on the animal inside her because she will need every ounce of savagery and ferocity that she can muster. Reed just sits in the back of the car awkwardly (for those who were wondering.)

~~~

Liam admits he's amazed it worked saying that he thought he would tear Stiles and Derek apart. Stiles says that would have made for an awkward ride home. Derek wonders if he can bring the same level of control and strength in the fight ahead. Liam flicks out his claws to demonstrate that he can.

They arrive at La Iglesia, Derek is opens the door of the car and immediatly gets picked up and thrown out by a waiting Berserker. He's stabbed repeatedly by the creatures bone "fist dagger". Liz says a few things in Latin that are supposed to be spells but nothing works and she starts to stress, making it absulutly fail until Braeden attacks with a rapid fire shotgun sending it fleeing.

Derek can't stand. He's bleeding badly. He says he's fine and urges the others to find Scott. He says he'll be right behind them but none of them believe this. His final words to Stiles are "save him." Stiles hesitates and looks back at Derek but then enters the church with Peter, Malia, Reed and Liam. Braeden and Liz stay behind with Derek. Liz again tries some spells but they won't work.

~~~

Inside the church, Stiles phone rings - it is his father. The sheriff is angry saying he plans to hobble Stiles. He then asks for reassurance that Stiles is alright and safe. Stiles says he can't lie. He says the sheriff needs to go look for Lydia and Cheryl. He says if a berserker is involved the sheriff will need to take lots of firepower.

Scott, disguised in his berserker bones, attacks them and chases them deeper into the temple.

Braeden and Liz refuse to leave Derek but they hear berserkers coming and Derek says she'll need to concentrate on saving herself. Liz nods and Breaden gets up to investigate. Braeden circles around a building and spots Kate and one of her berserkers coming up the street.

~~~

Lydia says she no longer hears the berserker in the basement but Mason says there is only one way out. Lydia says they have to check and see if he's blocking the exit.

"It's still there" Cheryl says.

"Are you alright?" Mason asks and suddenly notices the bone sticking out of her side.

"I can't get it out" Cheryl explains, clearly in pain.

~~~

Malia tosses Kira's sword to Stiles and tells him to go find her and Scott. Reed goes with him in case Stiles is met by Kate. Malia, Liam and Peter turn to face the berserker.

~~~

Braeden is rapid firing at the berserker with Kate, first with a shotgun then with her pistols. None of it has any effect and the berserker grabs her around the throat and lifts her into the air. Kate asks how much Braeden was paid. The mercenary says "way more than you're worth."

The sound of engines heralds the arrival of two SUVs filled with Mexican hunters. Araya and her "family" arrive with Chris and Parrish. Everybody opens fire on the Kate and the berserker. Braeden is forgotten and sits in the dust.

"Selene go! Find Scott!" Chris yells and Selene nods, running towards the church.

~~~

Stiles and Reed are searching deep in the temple and find Kira. She explains that Kate has turned Scott into a Berserker. Stiles realizes that's why the kept Lydia away – so Scott's friends won't know who they're killing.

~~~

Malia, Liam, and Peter all take runs at the Berserker and get in some good punches but he rebuffs each in turn. Suddenly they hear a roar and all turn to see Selene at the entrance. The Beserker charges at her.

~~~

Kate runs from the Calaveras who continue to fire on her. Derek is sitting off to the side, dying.

"No, no no. Come on stupid spells. Come on Liz, it's a simple healing spell" Liz mumbles to herself.

"It's okay" Derek breathes out and dies.

Kate's berserker takes out several hunters while she hides in the cover of one of their trucks. Braeden makes it back to Derek. Liz shakes her head and she sobs.

~~~

Lydia decides to go after the berserker with a baseball bat. Mason doesn't think it will work. Lydia says her friends are in trouble as is Mason's best friend Liam so she plans to "go for it." When Lydia and Cheryl stand to face the creature alone, Mason comes screaming past them with a bat to attack. The berserker makes quick work of them both, sending them flying back down the hall. Cheryl punches the Berserker but can'tuse her claws or fangs because of Mason. The Berserker then also throws her back, she slides a little further than Lydia and Mason. It then comes after them. Mason says he thought the thing just wanted to keep them from leaving. Lydia says it must have changed its mind.

The berserker's advance is halted by the sheriff's voice saying "excuse me – catch!" He then tosses it a metal rectangular container of some sort which the creature catches. The lettering on the top says "Front Toward Enemy." It is a Claymore Mine. Cheryl pulls Lydia and Mason behind a wall and the Sheriff takes cover. The sheriff triggers the mine. It explodes and turns the berserker into bone fragments and dust.

"You guys okay?" The sheriff asks.

"It was after me. It wanted me to stay in Beacon Hills. I think this was all some sort of distraction" Lydia realises.

"Because you knew they're trying to kill someone" The sheriff adds.

"Kill who?" Mason asks. "...Scott" Lydia replies.

~~~

The Berserker managed to get a bone dagger into Selene's abdomen. He pushes her against the wall and starts to choke her. She then looks into it's eyes and her own become big.

"Scott" She chockes out. "Scott it's me. Scott you're stronger than this. You can fight this" She struggles to get free. "Scott, I know you don't wanna hurt me" The Berserker squeses her throat harder. "Scott, this... this isn't you! You're not a monster! Or a... Or a killer! Scott you're a True Alpha! Like me" the Berserker, who was about to punch her halts his movements. Selene glows her eyes their Alpha colour and the eyes underneath the maks glow the same colour back.

"Guys! It's him! It's Scott!" Stiles yells as he runs into the room.

~~~

Braeden is crying over Derek's dead body as Kate begins taking out hunters one by one. Everyone, including Braeden, Chris, Parrish, and Araya, opens fire again. Parrish says he's running out of ammo and the berserker isn't going down. Chris loads what appears to be a bullet filled with Yellow Wolfsbane into his pistol.

~~~

Scott puts selene to the ground and her knees are weak. She begins to fall to the ground but bfore she can Reed catches her. Everyone then turns to Scott/the Berserker. He then seems to struggle, tearing off the pieces of bone armor. He reaches up and rips the bear skull from his head in two pieces with a mighty roar. The skull comes apart with a flash of golden light. Selene's face then turns from relieved to furious. She turns to Peter, letting go off Reed and instead leaning on a wall.

"It was you" She scoffs and starts walking closer. "The only one who knew as much as Argent about the Berserkers... about the Nagual. You taught Kate. You helped her. All for power" Selene seems disgusted by even the thought.

"My family's power... to be rightfully inherited by me. Not usurped by some idiot teenage boy so incorruptible, he won't shed the blood of his enemies even when justified. You don't deserve your power. Not power like this" Peter says to Scott. Selene growls but Scott puts a hand on her shoulder. They nod a each other, silenty agreeing she can't fight him with a giant gash in her stomach.

With eyes glowing blue, Peter goes through a transformation that includes much head twisting and bone cracking. His forehead becomes more triangular and pronounced with deep ridges. His ears enlarge and point and he has bigger fangs than we've seen on him before.

Malia also transforms and comes at her father. He bats her away, slamming her into a large broken stone wall. Peter apologizes with a "I'm sorry sweetheart, we'll talk about this later." Kira gets ready with her sword but Scott calls her off too.

"You were my Beta first, Scott. It was my bite that changed your life... and my bite that can end it" Peter taunts. Selene goes back to leaning against Reed who slwoly puts her down on the floor. He pulls out the bone dagger and then turns around, cruious to see how this exchange from Peter and Scott goes.

"Then end it, Peter! Because you won't get another chance" Scott explains. Both growl and launch themselves, crashing into each other in the air.

~~~

Outside, the berserker is still tearing a path through the Mexican hunters. Braeden fires past Derek's dead body as Araya confronts Kate directly. Kate taunts the older woman saying she's coming for her next. Araya says come on and she flips out an electrified cattle prod. Just then a howl echoes off the ruined buildings. Braeden looks to where Derek's body layed just moments before but it is now gone.

A black wolf with glowing blue eyes comes bounding over a broken wall. It attacks Kate and takes her down, snarling and biting. Kate screams and tries to crawl away from the wolf which is slowing transforming into a man. A naked Derek Hale now stands in the dirt street. Kate is shocked. She whispers, "You're dead." Derek says, "No. I was evolving, something you'll never do."