Scott shifts at Lacrosse training. Stiles helps him to get to the locker room. Derek watches the whole event from the sidelines. I think this is the first time Derek really notices Stiles.

Stiles and Scott talk via AOL messenger. Stiles is the one who spots Derek lurking behind Scott in the back of his room. This is the second time he sees Derek first.
Derek smashes Scott against the wall. Oh. Oh. The wall smashing thing. Is it a werewolf dominance thing? Is it a Derek thing?
Derek threatens to kill Scott if he plays the game on Saturday and shifts in front of everyone. Meaning everyone will hunt after the werewolves then. Stiles watches the intimidation attempt thanks to the magic of AOL Messenger. He sees Derek attacking his friend and threatening his life. Derek is the bad guy now, not just a bad wolf.

Scott: "Curfew because of the body."
Stiles: "Unbelievable. My dad's out looking for a rabid animal, while the jerk-off who actually killed the girl is just hangin' out, doing whatever he wants."
Scott: "Well, you can't exactly tell your dad the truth about Derek."
Stiles: "I can do something."
Scott: "Like what?"
Stiles: "Find the other half of the body."
Scott: "Are you kidding?"

Stiles appears frustrated and angry by Derek's audacity to run free, though, he seems to be a killer. So Stiles plans to find the other half of the body to make Derek pay for the effrontery of making his life stressful. Scott isn´t thrilled about the plan. All he cares about is Allison. All Stiles cares about is to put Derek to jail. His use of the term jerk-off as an insult is pretty interesting. Not bastard or asshole or jerk, but an insult that is basically a sex act. So does he subconsciously sexualizing Derek even when he just wants him to go away?

Scott: "Derek! Derek! Stay away from her! She doesn't know anything!"
Derek: "Yeah? What if she does? You think your little buddy Stiles can just google werewolves, and now you got all the answers, is that it?"

Derek brings up Stiles out of the blue, completely unprompted. He may not have paid him much attention back in the woods when they first met, but here, now, Derek has understood that Stiles and Scott are a package deal and that Stiles is someone Derek has to deal with.

Stiles: "Okay, just so you know, I'm not afraid of you. Okay, maybe I am. Doesn't matter. I just wanna know something. The girl you killed... she was a werewolf. She was a different kind, wasn't she? I mean, she could turn herself into an actual wolf, and I know Scott can't do that. Is that why you killed her?"
Derek: "Why are you so worried about me when it's your friend who's the problem? When he shifts on the field, what do you think they're gonna do. Just keep cheering him on? I can't stop him from playing, but you can. And, trust me... you want to."

Stiles and Scott get Derek arrested. Stiles enters the police car in the front talking to Derek sitting in the back. This is the first time they interact with each other.
Stiles starts out nervous, curious, afraid, and once he drops his gaze - what is he looking at? Derek´s crotch? He wants to know what Derek is trying to hide.
Derek glares at him, and when he speaks, it's all about trying to stop Scott from playing that game. Derek just lost his sister and some idiots dug up the grave, got him arrested, and still he's trying what he can to stop them from making stupid mistakes. He's giving Stiles a last push to save Scott. Why? Because he probably thinks Stiles can actually accomplish this. Because he's now seeing Stiles as someone who can get shit done.
The way they look at each other, the way Derek leans closer to Stiles and says "trust me", and then he hesitates for a second, dropping his eyes as if he has smelled something about Stiles he hadn´t expected. Whatever it is Derek looks pretty confused about it.

First Derek wears a white shirt, later a black shirt. Stiles wears a color-purpled shirt with the imprint Cabaret du Neant.

Stiles: "The, uh, medical examiner looked at the other half of the body we found."
Scott: "And... "
Stiles: "Well, I'll keep it simple. Medical examiner determines killer of girl to be animal, not human. Derek's human, not animal. Derek not killer. Derek let out of jail."
Scott: "Are you kidding?"
Stiles: "No, and here's a bigger kick in the ass. My dad I.D.'d the dead girl. Both halves. Her name was Laura Hale."
Scott: "Hale?"
Stiles: "Derek's sister."

The way Stiles presents the information that Laura is Derek's sister implies that he understands how much more complicated this situation suddenly is.
Do they hate each other? I think Derek has a good reason to hate Stiles for what he did to Derek by digging up Laura's body. But does he? Again. Hard to tell. He´s angry. That´s for sure.
Stiles is mostly afraid of what might happen to Scott and besotted from the thrill of the chase and the mystery of Derek. Oh yeah. There is no denying. Stiles enjoys having this adventure just a little bit.