Hostage situation. Matt is a crazy serial killer. Stiles and Derek spent most of the time in close physical proximity.

The sheriff: "I mean, why would this kid want most of the 2006 swimteam and his coach dead?"
Stiles: "Isn´t it obvious? Our swimteam sucks! They haven´t won in, like, six years." LOL!

The sheriff rather trusts Scott than his own son. Well! No wonder why. So the trust matter is as important to Stiles as it is to Derek. Oh!

Stiles recognizes Matt by the back of his head and his leather jacket.

Stiles: "How many people do you know that wear black leather jackets?" Hello. Derek. Duh!
The sheriff: "Millions, literally." Exactly. You just see this as something extraordinary because you have a crush on Derek. *grins*

Stiles about Matt: "He looks evil." For the second time. If you would know how you will look being possessed and quite evil?

Stiles: "If one´s an incident, two´s a coincidence, and three´s a pattern, what´s four?" We ask ourselves that many times in this series?

Deaton brings Derek out of his unconsciousness with a dog whistle. LOL! Deaton outs himself as the confident of Derek´s mother. The Hale´s Emissary.

Deaton: "Don´t worry. You´re still an alpha. But, as usual, not a particularly competent one."

Deaton warns Derek not to listen to Peter. He cannot trust Peter.
Derek: "I don´t trust anyone."
Deaton: "I know. If you did, you might be the Alpha you like to think you are. And unfortunately, the one person you should trust doesn´t trust you at all."
Derek: "Scott."

Really? Deaton never said a name. Derek just guessed the most obvious. Maybe it is not Scott he should trust.

Derek arrives at the precinct and is immediately paralyzed by the kanima. He falls to the ground. Stiles risks a lip and is paralyzed, too. He falls right on top of Derek. Oh, this is so much fun.

Derek: "This is the one controlling him? This kid?"
Matt: "Well, Derek, not everyone's lucky enough to be a big, bad werewolf. Oh, yeah, that's– that's right. I've learned a few things lately. Werewolves, hunters, kanimas. It's like a frickin' Halloween party every full moon. Except for you, Stiles. What do you turn into?"
Stiles: "Abominable snowman. But, uh, it's more of, like, a wintertime thing, you know, seasonal."
Scott: "Hey!"
Stiles: "You bitch."
Derek: "Get him off of me."
Matt: "Oh, I don't know, Derek. I think you two make a pretty good pair. It must kinda suck, though, to have all that power taken away from you with just a little cut to the back of the neck. I bet you're not used to feeling this helpless."
Derek: "Still got some teeth. Why don't you get down here a little closer, huh? We'll see how helpless I am."
Stiles: "Yeah, bitch."

Derek gets his sarcasm all over Matt even though he can't even move. This is worse than the time at the pool, even, because the water was actually working for them then, and ultimately Stiles himself wouldn't have been in danger for a while (if he'd let Derek go, he could have floated in the pool for hours). But this time, Derek has nothing to lean on. And still he's got that dry banter going for him - a trait I'm sure Stiles appreciates, considering the Abominable Snowman quip. These two are incredibly in sync. It could be seen as if Derek is objecting to Stiles on top of him for reasons. Derek's motivation could be that he doesn't want vulnerable Stiles between him and danger. Or that the proximity does cause some physical reaction and he doesn't want Stiles to know. Or he can't breathe with the extra pressure and being paralyzed and all. Neither of them actually objects to the "good pair" line, which is probably half not wanting to give Matt the satisfaction and half not giving a fuck if they give that impression. But if they really hated the implication, I'm sure they would have thought of something. Stiles backing up Derek's threat is also possibly one of the cutest things ever. He's like a mouse roaring with a toothless lion. Neither of them can do anything.

Stiles: "Scott, don´t trust him!"

Matt pulls Stiles off of Derek and puts his shoe on Stiles´s throat, choking him. Derek's witness to this reckless moments, his eyes flick to Stiles when he yells, almost like Derek can't believe this idiot would call attention to his pale-skinned, fragile-boned body in a situation like this.

Matt reveals that he's looking for the bestiary, because he is turning into a kanima himself. Stiles and Derek look at each other like "whoa, did you get that? WTF?!" They are truly in sync, they just click with each other.

The Argents are on their way. Allison wants Derek dead for what he did to her mother. Gerard, her bastard grandfather manipulated her pretty well.

Stiles: "Hey. You know what's happening to Matt?"
Derek: "I know, the book's not gonna help him. You can't just break the rules, not like this."
Stiles: "What do you mean?"
Derek: "Universe balances things out. Always does."
Stiles: "Is it because he's using Jackson to kill people who don't deserve it?"
Derek: "And killing people himself."
Stiles: "So if Matt breaks the rules of the kanima, he becomes the kanima?"
Derek: "Balance."
Stiles: "Will he believe us if we tell him that?"
Derek: "Not likely."
Stiles: "Okay, he's gonna kill all of us when he gets that book, isn't he?"
Derek: "Yep."
Stiles: "All right, so what do we do? Do we just– do we just sit here and wait to die?"
Derek: "Unless I can figure out a way to push the toxin out of my body faster. Like triggering the healing process."
Stiles: "Wha– oh, what are you doing? Aw, gross."

Casual, sarcastic banter. Derek comfortable sharing not just information but philosophy. Stiles not being impressed by Derek's self-sacrificing routine. This is Derek and Stiles working stuff out between them, bouncing ideas between them, and Stiles' slightly squeamish side plus Derek's tendency to go for the solution that involves him and pain.

Stiles: "So is that hypothetical situation we talked about getting any less hypothetical?"
Derek: "I think so. I can move my toes."
Stiles: "Dude, I can move my toes."

Look, it's failwolf! It's Stiles calling Derek "dude"! It's banter about toes! Whether you think they're potentially attracted to each other or not, these are two dudes who are comfortable with each other and who work well together under pressure, but the casual nature of this exchange implies something even greater: a hard-fought-for-and-won friendship that can blossom into anything.

The Argents arrive. A firefight starts. Scott gets to Stiles and Derek.

Derek: "Take him! Go!"

Derek is telling Scott to take Stiles out of danger. It shows that Derek cares about Stiles´s welfare. Telling Scott that is completely redundant, because Scott's priority is always going to be Stiles. He was already grabbing for him. Derek sounds, if not panicked then certainly worked up, wanting Stiles out of the firing line as quickly as possible. It is such a strange little show of caring that Stiles looks at Derek, twice, possibly to check if this is still the same dude who once pushed his face into a steering wheel. It's not, not really. Derek's changed a lot since then. Hey. This is the boy who held him above the water for over two hours and almost drowned himself. Of course, Derek cares. He would never let anything happen to Stiles.

Derek comes for Matt and essentially saves the Sheriff and Melissa while Stiles watches, unable to do anything. Derek could have gone after Matt, but he stayed around to keep the kanima away from the incapacitated humans. Stiles notices, and he pushes himself back into the shadows, when Derek gets knocked out for a moment. It's important because there is no person more precious to Stiles than his dad and watching this, being unable to do anything is already causing Stiles a great deal of anxiety. Knowing that Derek would risk not just his own life but a strategic advantage that might save more people in the long run by taking out Matt for Stiles and his dad and Melissa. This is huge.

Melissa learns that her son Scott is a werewolf. Great tearjerker moment.

Derek overhears Scott talking to Gerard. Derek certainly doesn´t trust Scott now.

Gerard drowns Matt in a riverbed. This moment is the sheer horror. Matt, who almost drowned at the age of nine and had no greater fear than drowning since then, dies a horrible death. I was never able to really watch that scene altogether.

Peter watches in shock that Gerard is the new master of the kanima.

They don´t hate each other, no, they tolerate each other.

Stiles wears the same outfit as in 2/9. First Derek still wears the grey undershirt from 2/9. At the precinct he wears a dark grey/black longshirt.

Overall this is the best episode of the whole season.