Stiles is scared of Derek. Derek suffers. Stiles is not that afraid anymore.

Stiles: "If Derek isn't the Alpha, if he's not the one who bit you, then who did?"
Scott: "I don't know."
Stiles: "Did the Alpha kill the bus driver?"
Scott: "I don't know."
Stiles: "Does Allison's dad know about the Alpha?"
Scott: "I don't know! Jeez."
Stiles: "Dude, you need to study more. That was a joke. Scott, it's one test. You're gonna make it up. Do you want help studying?"
Scott: "No. I'm studying with Allison after school today."
Stiles: "That's my boy."
Scott: "We're just studying."
Stiles: "Uh, no, you're not."
Scott: "No, I'm not?"
Stiles: "Not if I'm forced to live vicariously through you. If you go to her house today and squander that colossal opportunity, I swear to God I'll have you de-balled."
Scott: "Okay. Just... Stop with the questions, man."
Stiles: "Done. No more questions. No more talk about the Alpha or Derek. Especially Derek... who still scares me."

Scott doesn't like Derek. Stiles on the other hand is curious and annoyed by his existence. Unlike Scott he himself has no prospects in having a sexual adventure. The way he mumbles that Derek still scares him is pretty suggestive. And the expression in his eyes! Like he thinks about very different things that Derek could do to him just right now. X-rated things. Yes. Derek scares Stiles. But in more ways than Stiles likes to admit. Derek is a mystery and he's hot. Stiles is sexually frustrated and Derek is way above and beyond the scary monster that bit Scott. Stiles doesn´t know how to deal with a guy like Derek. Stiles doesn´t know how to deal with the feelings he has because of Derek.

Stiles: "You've gotta be kidding me. This guy's everywhere--"
Scott: "What the hell? What are you doing here?"
Derek: "I was shot."
Stiles: "He's not looking so good, dude."
Scott: "Why aren't you healing?"
Derek: "I can't. It was--it was a different kind of bullet."
Stiles: "A silver bullet?"
Derek: "No, you idiot."
Scott: "Wait, wait. That's what she meant when she said you had 48 hours."
Derek: "What? Who--who said 48 hours?"
Scott: "The one who shot you. What are you doing? Stop that!"
Derek: "I'm trying to tell you, I can't!"
Scott: "Derek, get up! Help me to put him in your car."
Derek: "I need you to find out what kind of bullet they used."
Scott: "How the hell am I supposed to do that?"
Derek: "'Cause she's an Argent. She's with them."
Scott: "Why should I help you?"
Derek: "Because you need me."
Scott: "Fine. I'll try. Hey get him out of here."
Stiles: "I hate you for this so much."

Derek plants himself in front if Stiles's jeep and hopes for the best. Stiles is shocked, then annoyed by Derek´s appearance. So how does Derek know about Stiles's jeep anyway? How is it easier for him to find Stiles than Scott? By scent? By knowing his car?
Stiles's curiosity picks up and he blurts out the question about the silver bullet. Derek calls him an idiot, for a moment back in control, like Stiles keeps him focused.
Stiles' frustrated "I hate you for this so much" to Scott is full of feeling. Feeling what? It doesn't sound like fear or apathy or dislike. Stiles doesn't want to deal with Derek, and the reasons for that are complicated like "I find you attractive" but "I can´t deal with you". Not now. Not like this. Not ever. So stay away from me.

Stiles: "Hey, try not to bleed out on my seats, okay? We're almost there."
Derek: "Almost where?"
Stiles: "Your house."
Derek: "What? No, you can't take me there."
Stiles: "I can't take you to your own house?"
Derek:" Not when I can't protect myself."
Stiles: "All right. What happens if Scott doesn't find your little magic bullet? Hmm? Are you dying?"
Derek: "Not yet. I have a last resort."
Stiles: "What do you mean? What last resort? Oh, my God. What is that? Oh, is that contagious? You know what, you should probably just get out."
Derek: "Start the car. Now."
Stiles: "I don't think you should be barking orders with the way you look, okay? In fact, I think if I wanted to, I could probably drag your little werewolf ass out into the middle of the road and leave you for dead."
Derek: "Start the car, or I'm gonna rip your throat out... With my teeth."

Stiles is frustrated because Derek is messing up his plan of getting rid of him as fast as possible. Derek affects Stiles, emotionally. Whatever he feels about Derek, he feels a lot of it. Their back and forth banter is equal in nature. Neither of them seems inclined to back down. When Stiles does give in it does not appear to have anything to do with fear. Derek is surprisingly in control for someone who was near to wolfing out before. Stiles annoys him but Derek only threatens to kill Stiles after Stiles threatens to leave him for dead in the middle of the road. Not very nice. So no surprise that Derek counterattacks in the vulnerable state he is in right now.
Scott's phone says 3:51 p.m.

Check against how Stiles refuses to leave Derek dying in the middle of some road until Derek begs him to go and save Scott in 4x12. Just saying!

Stiles: "What am I supposed to do with him?"
Scott: "Take him somewhere, anywhere."
Stiles: "And, by the way, he's starting to smell."
Scott: "Like--like what?"
Stiles: "Like death."
Scott: "Okay, take him to the animal clinic."
Stiles: "What about your boss?"
Scott: "He's gone by now. There's a spare key in the box behind the dumpster."
Stiles: "You're not gonna believe where he's telling me to take you."
Derek: "Did you find it?"
Scott: "How am I supposed to find one bullet? They have a million. This house is like... the fricken Walmart of guns."
Derek: "Look, if you don't find it, then I'm dead, all right?"
Scott: "I'm starting to think that wouldn't be such a bad thing."
Derek: "Then think about this. The Alpha called you out against your will. He's gonna do it again. Next time you either kill with him or you get killed. So if you wanna stay alive, then you need me. Find the bullet."

After hours they are still sitting under that tree where Stiles parked the jeep, waiting for news from Scott, with no distraction but each other. What did they do all those hours? Did they talk? Did they sulk in silence? I´d like to know.
Stiles is unafraid to complain to Scott about Derek's smell. Derek doesn't protest about the "smells like death" quip, doesn't grab the phone out of Stiles' hand or is in any way aggressive toward Stiles. But he looks hurt and desperate. He definitely looks like he hates Stiles right now. When Stiles hands the phone over to Derek their hands touch. Derek closes his eyes like he is savoring Stiles's touch. It´s the first time he touched Stiles without having a reason.

Stiles: "Does Northern blue monkshood mean anything to you?"
Derek: "It's a rare form of wolfsbane. He has to bring me the bullet."
Stiles: "Why?"
Derek: "'Cause I'm gonna die without it."

Derek is not angry anymore. He's also not pleading for his life. Derek speaks about his death like he thinks Stiles is going to care. And from the look in Stiles' eyes, it seems he does. Why? Only a few hours ago Stiles said Derek scares him, and that he hates Scott for putting him into this position, right? So what has changed? Why does he suddenly care about Derek dying?

Stiles: "Okay. You know, that really doesn't look like anything some echinacea and a good night of sleep couldn't take care of."
Derek: "When the infection reaches my heart, it'll kill me."
Stiles: "Positivity just isn't in your vocabulary, is it?"
Derek: "If he doesn't get here with the bullet in time... Last resort."
Stiles: "Which is?"
Derek: "You're gonna cut off my arm."

Entering the operating room of the animal clinic Derek shortly relies on Stiles to keep his balance by resting his hand touching again! on Stiles´s shoulder. Stiles is trying to reassure either Derek or himself that it's not as bad as it looks, and he's doing a terrible job of it. Derek just keeps talking, sharing the facts, something Derek has been patently reluctant to do before. And then he asks Stiles to cut his arm off. Wow! What is this? Desperation or trust? The look on Stiles´s face is priceless.

Stiles: "Oh, my God. What if you bleed to death?"
Derek: "It'll heal if it works."
Stiles: "Ugh. Look... I don't know if I can do this."
Derek: "Why not?"
Stiles: "Well, because of the cutting through the flesh, the sawing of the bone, and especially the blood!"
Derek: "You faint at the sight of blood?"
Stiles: "No, but I might at the sight of a chopped-off arm!"
Derek: "All right, fine. How about this? Either you cut off my arm, or I'm gonna cut off your head."
Stiles: "Okay, you know what, I'm so not buying your threats any-- Oh, my God. Okay. All right, bought, sold. Totally. I'll do it. I'll do it. What? What are you doing? Holy God, what the hell is that?"
Derek: "It's my body... Trying to heal itself."
Stiles: "Well, it's not doing a very good job of it."
Derek: "Now. You gotta do it now."
Stiles: "Look, honestly, I don't think I can."
Derek: "Just do it!"
Stiles: "Oh, my God. Okay, okay. Oh, my God. All right, here we go!"

Stiles and Derek banter around the fact that Stiles really doesn't want to cut Derek´s arm off. Derek´s threat to cut off Stiles´s head is lost because Stiles has already figured out that Derek´s threats are empty and tells him that. Derek grabs Stiles by the shirt and pulls him face to face. That works in the way to make Derek calm down and somehow giving up. Is it Stiles´s scent that messes Derek up? Then Derek vomits and Stiles decides to use the bonesaw even he is freaked out. Derek orders him to do it, sure, but Stiles looks like he wants to save Derek not because he is afraid of him.

Scott: "Stiles!"
Stiles: "Scott?"
Scott: "What the hell are you doing?"
Stiles: "Oh, you just prevented a lifetime of nightmares."
Derek: "Did you get it?"
Stiles: "What are you gonna do with it?"
Derek: "I'm gonna... I'm gonna..."
Scott: "No. No, no, no, no."

Scott´s arrival is a relief. Derek is holding the bullet and Stiles asking him what he wants to do. Derek actually tries to answer before he passes out. He tells Stiles stuff when he clearly hated to share even pertinent info like "I didn't bite you, Scott" until it was almost too late.

Stiles: "Derek. Derek, come on, wake up. Scott, what the hell are we gonna do?"
Scott: "I don't know! I can't reach it."
Stiles: "He's not waking up!"
Scott: "Come on."
Stiles: "I think he's dying. I think he's dead!"
Scott: "Just hold on! Come on. Oh! I got it! I got it!"
Stiles: "Please don't kill me for this. Ugh! Ow! God!"
Derek: "Give me..."
Scott: "Up!"
Stiles: "Ow! God..."

Derek passes out. The bullet rolls away. Scott goes after the bullet. Stiles goes for cradling Derek's face and panicking about the fact that he's not waking up. And then cradling his face some more. Touching! That´s about the man that scares him. Interesting! Stiles punches Derek in the face to wake him up and it works. Derek's reaching for the bullet and then for Stiles, in that order.

Stiles: "That...Was...Awesome! Yes!"
Scott: "Are you okay?"
Derek: "Well, except for the agonizing pain."
Stiles: "I'm guessing the ability to use sarcasm is a good sign of health."

Derek does the whole magic healing thing. He even growls like a wolf. Stiles watches Derek writhing half naked on the floor, licking his lips - twice! Whoa! Then he yells "THAT WAS AWESOME!" like this was the best thing ever happening to him, sounding like he just came in his pants. Scott is looking at him like "What the fuck is wrong with you, dude? I thought you hate him." Next Stiles makes the "ability to use sarcasm is a good sign of health," comment which presents him with one of Derek´s deadly glares. The slight smile playing on Stiles´s lips fades off in a split second. Derek is back to being annoyed by this human boy. Stiles appears to be back of being afraid of the bad wolf. Or isn´t he?

Stiles wears a light-grey striped shirt over a grey shirt with a green imprint - Derek wears a dark shirt, later he is pretty much bare-chested.

Stiles is in danger of falling for a bad boy. He is not the first girl boy making that mistake.