Previously on Teen Wolf...
The name Sebastien Valet has been forgotten.
They took him and I couldn't do anything.
We can find him.
True evil only comes by corrupting
something truly good.
Mason!
Who the hell was that?
Sebastien Valet.
You knew, didn't you?
I wasn't certain, but I suspected.
Although, it makes sense that Marie-Jeanne's pike would be reforged into something
that could appear as innocuous as a cane.
But will it kill him?
You're damn right it will.
Vanishing twin syndrome...
This is part of your expertise, right?
Not particularly, no.
He's still alive.
This looks bad, Theo.
I'll be fine.
Maybe we need to stop.
Or figure out another plan.
Just take a couple more days to think about it.
Days? You want to wait days?
You're hurt. You need time to heal.
And I'm not like the others.
I can't take your pain.
I know,
and that's okay.
Because you can do something else for me.
You can give me your power.
Theo...
Theo, stop...
And then there were none.
Who are you calling, Malia?
Is it Stiles, your boyfriend?
Tell him to come. Bring all your friends, if you want.
Go ahead, Malia.
You tell me how many people I'm going to have to kill tonight.
Can you keep him alive?
I'm not sure he technically is alive.
Screw keeping him alive. How do we get him to talk?
Personally, I don't think we utilize torture nearly enough.
Come...
Did you hear that?
Come to me...
To me.
Liam, wait!
Stop.
It's electrified.
Marcel...
If this is what immortality looks like,
I think you might have been misled.
For you...
All for you...
What did you do with it, Marcel?
Where is the pike?
The Argents...
The cane.
But they took it. They took the cane.
I lost him.
Sebastien's going to know we have the pike.
And if he doesn't, he's going to figure it out soon enough.
Then what do we do?
We stop chasing him. And make him come to us.
Almost, Braeden. But not quite.
You'll get another chance.
But you better make sure it's a head shot.
Coming down, Malia?
Malia, don't move!
Maybe there's something in here.
Something about how he was a Genetic Chimera.
Mason had a vanishing twin.
Now we've got a vanishing Mason.
What does that have to do with him turning into a 250-year-old French guy?
How does that even happen?
Hold on, Scott might have something.
Mason's twin wasn't entirely gone. That's what made him a Genetic Chimera.
The DNA was still there.
Metaphorically speaking, the DNA of Mason could still be inside Sebastien as well.
How?
Life is energy. Energy doesn't just disappear.
The Dread Doctors may have found a way to break the rules of the supernatural world
but there are some rules that simply won't break.
So Mason can't just be gone?
Somewhere in Sebastien he has to still exist in some form.
A spark of energy, a flicker of memory.
Hang on...
Liam, you said Mason said something
right before he turned.
He said, "That's not my name."
He finally remembered his name.
Damnatio Memoriae.
That's what they wanted.
They wanted Sebastien to remember his name.
Scott, you know the myth of what happens when you call a werewolf
by its given name?
It turns back to human.
What does that mean?
Someone can just walk up to the Beast,
yell Mason's name and turn him back?
Not someone...
Lydia.
Who did you say you were looking for?
The man's name is Argent.
Did you say Argent?
Sorry. My son likes to send incredibly long and incredibly confusing messages.
Maybe I should just turn the damn thing...
So...
You're looking for one of the Argents?
You seem to know who I am.
That means you know what I'm capable of.
I've got some experience.
Your weapons may be more sophisticated
than the arrows and the bullets of my time,
but they still won't kill me.
I'm pretty sure a nine millimeter Beretta will do more damage
than an 18th century musket.
Are you certain?
I can walk out of this place with my hands clean.
Or, I can walk out with them drenched in blood.
Your choice.
Sir?
Clark, don't.
Stop where you are.
Let him go.
No!
Hayden.
Your name is Hayden.
Melissa...
Melissa!
Malia. Come down.
Don't listen to her.
I'm not going to stop, Malia.
I'm taking back what you stole from me.
I didn't steal anything.
But you did.
And I don't care if you were a willing participant or not.
Talia Hale spent nine months trying to convince me of the miracle of childbirth.
You know what it really felt like?
A parasite.
Talia said it was a gift...
That the coyote passes down part of her power to her daughter.
She called it beautiful.
I call it theft.
Where is it?
I brought you here like you wanted.
How about letting me go now?
This demon, on the left. What is he?
He's called a Hellhound.
Parrish... His name is Parrish, isn't it?
And the Argents will try to put the pike in his hands.
When did young people become so confident?
I know that sound.
It's the Argents, isn't it?
Drawing the Beast to them. Corralling it.
You'll need to be back at full capacity.
Let's find out.
Looks like it worked.
You know, Theo,
someday your willingness to stab anyone and everyone
in the back might turn out to be your downfall.
Don't worry. You can still have Scott's eyes.
I'll just be bringing them to you.
Hey. You all right?
Did...
Did you find something?
A solution?
Yeah. It was you.
It was you, Lydia.
Lydia's been hurt. Badly.
It doesn't change anything.
What if she's dying?
If we don't stop Sebastien, she will die.
He's not just coming for the pike.
He's coming for anything that stands in his way.
Right now, that's all of us.
What are you doing?
You saved my life once.
Now, I'm going to save yours.
I'm not sure I'm getting the strategy here.
You're the strategy, Parrish.
You're the one in the fresco.
Put there as a reminder that the Beast isn't unstoppable.
Whoever painted it... They didn't see a guy with a gun facing down the Beast.
They saw you.
They saw a Hellhound.
Is she okay?
She's gonna be fine, but...
She can't really talk.
Then it's over, isn't it?
There's nothing we can do to save him.
Give me a second.
Hey, it's me. God, I wish you just picked up.
I hate leaving messages.
I always ramble. I always say stupid things
and when I finally get to the super important thing
that I'm supposed to say, the voice-mail cuts me off and...
Me again. I have to leave.
But I'm coming back to help. I promise.
Because you're right, Scott. If anyone's going to save Mason, it's you.
It's us.
Get up.
Why?
Because I've got an idea.
And because this isn't over.
Lydia, this is gonna have to be just between us,
since I can get fired for it.
It's a cortisone shot. It's gonna bring the inflammation down.
Not there.
Yeah, okay, I'm gonna need to leave.
You're not going anywhere.
Hold her hand.
Okay, fine. I'm not leaving, but I still might faint.
Okay. Here we go.
Okay, Lydia, this is gonna hurt like a bitch.
Okay. I'll get Malia.
Text me when you find Parrish. Hold on.
What is this? Something I've been working on for a while.
Just make sure Malia gets it.
Is it plan B? It was plan A.
Plan A never works.
This one will.
Hayden?
They said that you can help us when we get hurt.
Well, I think I'm pretty hurt.
He's not slowing down.
He will. They both will.
Damn.
Scott?
You hear that?
I heard that.
Lydia, save your voice.
Hey...
Lydia, get out of the water!
Sorry, Lydia.
Feel that, Scott?
Kanima venom.
Just let it happen. Let it go.
Let everything go.
No!
Stiles?
You hear that?
That's the sound of real power.
Another arrogant youth.
A contender to steal my name?
You think you can take it from me?
I just want your power.
No!
You lied to me.
You and Scott...
That's right, Theo.
The whole time.
It would've never worked.
It could have worked.
With Belasko's talons.
You broke my neck.
And good luck with that.
There's an access grate that leads to the sublevel.
I think we can get to Lydia there.
What about Mason?
We can still save your friend.
Let's go.
This just isn't my day.
This is a surprising alliance, Scott.
You and Deucalion?
How long have you been planning this clever little double cross?
About as long as he and I have been planning this one.
What are you doing?
I knew when I brought you back,
it would never be about saving lives.
Only about immortalizing your own.
Scott, go.
Go, now!
It's not the full moon, Malia.
But you know what? It's close enough.
Stop...
Malia.
I want my power back.
I want my family back.
Can someone please come and take this gigantic shard of glass out of my chest?
Please?
I'll do it.
Liam...
It should be me.
If you get me close enough, I'll do it.
We're not killing your best friend.
That belongs to me.
It's a family heirloom.
I'd like it back, please.
It's all yours. Just give us Mason.
Unfortunately, I would not know where to begin.
And while I've benefited from his memories,
I don't have much use for an alter ego.
You want it?
Come and get it.
Sorry I'm late.
You're strong. There's no doubt in that.
But neither of you fight with a killer instinct.
Let me show you how to go for the throat.
Liam, wait.
We can still save Mason.
Who's going to save you?
What kind of werewolves are you?
No!
Marie-Jeanne?
Mason!
I think you're gonna need to try it a little louder.
Mason!
Scott!
No!
Is everyone okay?
Not everyone.
The Skinwalkers have a message for you, Theo.
Your sister wants to see you.
Scott, help me!
No! No!
Scott! Help me, Scott!
No! Scott!
Help me!
Hayden, I've managed to stabilize the injury.
But considering you're a Chimera,
I don't know how, or if, you'll heal.
We can still take you to the hospital.
I've already died there once.
It's your choice.
I know.
You saved their lives.
Mason. Malia. Half the population of Beacon Hills.
That's got to feel pretty good.
It did. For a while.
But it's something you want to feel again.
Yeah.
Yeah, I think so.
Welcome to your future career in law enforcement.
You don't have to do this.
I made a deal with them.
And I need to.
It's not for my parents. It's not for you.
It's for me.
How long is it going to take?
As long as it takes.
Keep it for me.
Keep it safe.
But she'll be back. She still has to graduate.
That's the thing, though, I don't know...
When we started this school year,
I was so stressed about everyone ending up
in the same place after we graduate.
But I don't think it matters.
We always seem to find each other anyway.
Even Allison.
He didn't tell you.
It was in the tunnels...
When Sebastien had his hands around Scott's throat.
The guy probably didn't even know what he was doing.
His claws got into Scott's neck.
He was going to kill him,
but then he stopped
and he said a name...
Marie-Jeanne.
He saw Scott's memories.
He saw Allison.
They must have looked like each other.
I mean, maybe exactly like each other.
It gave Scott a chance to break free.
She saved him.
Allison saved his life.