Noel doesn't make an appearance until the first classroom scene, where he sits diagonally behind Stiles. He doesn't add to or change the canon conversation between Scott and Stiles. When Stiles talks about how Derek "still scares [him]", Noel laughs a bit, which earns him a glare from both Scott and Stiles. He clears his throat to try and hide his laugh, not looking at either of his friends. Cut to Derek stumbling along in the school hallway.
—
Noel is standing talking to Scott as he unchains his bike in the parking lot, and as soon as they see Derek, he runs over to the parking lot to help him.
While Scott basically interrogates Derek, Noel has a hand on the older man's back and is listening intently to him speak.When Derek's eyes flash for a second, Noel jumps back but immediately returns to holding Derek steady.
Noel helps Scott put Derek into Stiles' jeep, and Scott orders Noel to go tell the other students that everything was fine. Noel does so quickly and gets all the honking to stop. He runs back to Scott and gets in the backseat of the jeep. Stiles looks at him and says "Noel, let Scott and I handle this. This isn't really your world to be meddling in."
"It is now," Noel says in unison with Derek, both of them looking at each other before Derek's eyes flash blue again and he grunts in pain, turning to face forward while Noel lays a hand on Derek's shoulder. Stiles drives off with Derek and Noel, Jackson looking particularly confused by his cousin's role in all of this business.
—
In the scene in the jeep, Noel looks just as uncomfortable as Stiles from where he sits in the middle back of the jeep. When Derek says "Not when I can't protect myself" Stiles chimes in "You won't be by yourself. I'm dumping you there with hero boy in the backseat so you can have a little snack before you kick the bucket."
"Why does everyone think I'm going to eat him?!" Derek asks and lets out more noises to show his pain, Noel staying silent in the backseat as Stiles pulls over.
When Derek orders Stiles to start the car and Stiles refuses, Noel mumbles "Stiles, do what he says." Stiles turns to the backseat and says "You, shut the hell up for a second. You invited yourself into this, if it were up to me you wouldn't even be here to make your stupid little side comments. So watch what you freaking say."
Noel shrinks back as Stiles and Derek have their iconic "rip your throat out with my teeth" scene. The whole time Noel sits in the backseat with a very "I wish my dads would stop fighting" expression on his face. He tries not to laugh as Stiles starts driving, just sitting silently and minding his own business with a slight smile on his face.
—
Later when Stiles and Scott are talking on the phone, Stiles says "And by the way, he's starting to smell." "Like what?" Scott asks. "Like death," Stiles replies. "You sure that's not just Noel?" Scott asks, to which Noel replies "You know we're parked on the side of the road and I can hear you loud and clear, right Scott?" Scott ignores Noel and keeps talking to Stiles.
—
Noel helps Derek sit down when they get to the clinic, leaning against the cage up against the wall as Stiles reads off the translation from Scott to Derek. He listens intently, legitimately curious about werewolves and wanting to know more about the culture and items involved as Derek explains what Nordic blue monkshood is.
"What differentiates that from any other kind of wolfsbane?" Noel asks, crossing his arms and looking down at Derek. Derek replies in a strained voice "More powerful. Common wolfsbane is used to hold a werewolf mid-shift or at the very least make them go feral. But this type is used to kill. Painfully." He takes a pause to breathe before continuing "Scott needs to bring me the bullet."
"Why?" Noel asks, in the place of Stiles.
"Because I'm gonna die without it," Derek says, to which Noel puts his face in his hands and rubs over his skin helplessly. We see Stiles' face of concern as well before being directed back to the dinner scene at the Argents'.
—
Noel helps get Stiles into the operating room of the clinic, and immediately starts to inspect Derek's injury. Derek shrugs him away and insists on dealing with it himself while Noel goes and searches for any tools he can use to help Derek.
—
When Derek reveals that Stiles may have to amputate his arm, Noel faints on the spot and is caught by Derek with his good arm.
—
After Scott leaves the Argents' house and grabs his bike, he receives a text from Noel. His contact name in Scott's phone is "No Soul Noel", indicating that Scott may be a bit of a bully where the Whittemore boy is concerned. The text reads "If you don't hurry up, he's gonna die. Which means SHE'S gonna die." Scott more or less ignores the text.
—
When we reconnect with Stiles, Derek, and Noel, Noel looks a bit pale from where he stands beside Stiles.
"What if you bleed to death?" Stiles asks as Derek ties the band around his arm. "It'll heal if it works," Derek replies, and Noel looks skeptical. "But what if it doesn't work?" he asks, which earns him a look but no response from Derek.
When Derek threatens Stiles and grabs his collar, Noel says "Hey, hey, Derek, stop!" Derek then vomits black blood and urges Stiles to start cutting off his arm, which Stiles once again refuses to do. Noel then grabs the saw and commands Stiles to get out of the way. The other boy listens.
Noel holds the saw to Derek's arm and says "Stiles, hold his hand." Stiles is about to ask why, but one look from Noel and Stiles does as he's told. Noel turns on the saw and just barely presses it to Derek's skin, a single line of black blood oozing out of his small cut. Scott then enters the room, and Noel quickly turns off the saw and holds his hands out for Scott to give him the bullet. Scott, wanting to be the hero, doesn't give it to him and insists on giving it to Derek himself. Scott then trips and the bullet falls into the grate on the floor as Derek collapses to the floor.
"Good freakin' job, Scott!!" Noel yells and kneels beside Derek, trying in any way he can to ease the man's pain and wake him up with the help of Stiles. Noel then begins a rant through the tears in his eyes, saying "Why do you and Jackson have to be the heroes every single time?! Why can't you let someone else like me have the big save for once, why can't you hop off your high horse for a second and think about somebody else?!"
Scott, this whole time, hasn't been paying attention and has been trying to get the bullet out from under the grate. Stiles, however, seems to have heard what Noel had to say loud and clear. When Scott gets the bullet, Stiles snatches it from him and gives it to Noel. Noel acts on instinct, biting the tip off the bullet with a single flash of yellow eyes that fizzles back to his normal green just as soon as they had flashed. He shakes the contents of the cap of the bullet into his hand, then lights it on fire with the lighter in Derek's pocket. It sparks in his hand and burns his palm, but the adrenaline running through him allows him to push the powder into Derek's bullet wound with minimal initial pain.
Suddenly, Derek begins writhing in pain as the wolfsbane cures him, and Noel looks up and behind him. There stands Laura once again, saying "Find him and tell me."
Noel stands and asks "What did you just do? What did I just do?" he looks down at his red blistered palm and gasps, hissing in pain as his shock finally wears off. Laura takes his hand in both of hers and pulls his hand up to her mouth, kissing his palm and healing it instantly. She looks him in the eyes, saying "Protect him. Find him. Tell me." She then disappears and Noel looks down at the floor as Scott, Stiles, and Derek talk.
"Okay, we saved your life, which means you're gonna leave us alone," Scott says, to which Derek scoffs and says "He saved my life," with a tilt of his head toward Noel. Noel chews his lip and says nothing, just turning around to join the conversation while staring down at the palm that Laura had healed. Scott makes everything about himself again, and Derek proves him wrong as usual.
—
Noel accompanies Scott and Derek to the hospital, and when he sees Peter, he freezes in the doorway and refuses to enter the room. When the burnt half of Peter's face is revealed, Noel gasps and puts a hand over his mouth. He didn't need any extra convincing of the Argent's being evil deep down, but now he knows he was right to trust Derek from the get go. The last time you see him in the episode is when he leaves Peter's room with Scott and Derek.