Disclaimer: I don't own Teen Wolf.

...

Stiles' tree tattoo is fully healed in the morning, and he wakes to find himself curled up around Derek, his chest pressed up against Derek's back, despite the fact they went to sleep back-to-back the night before. Derek's still asleep and breathing peacefully, and Stiles is loathe to wake him. He carefully wriggles his arm out of the hold Derek has on it and flees to the bathroom, barely making it in time to relieve the urge in his bladder. He sighs, head resting against the tiles, running his tongue along his teeth as he waits for the stream to stop. Stiles finally finishes peeing (seriously, he's going to time himself one day, 'cause that's got to break a world record or something), flushes, and turns to wash his hands. He checks his teeth in the mirror as he lathers up with soap, using a frothy hand to turn on the tap. Then he stops short, staring at his arm and his heart races because he sure as fuck didn't have that tattoo on his forearm yesterday.

Stiles turns around abruptly, trying to see if his actual tattoo is still there, and he sighs in relief because it's there. It's darker than it was before, but there's no blood thankfully, and Stiles flexes his shoulder blades, grinning as the branches move with the motion. Then he follows the uppermost branches as they weave and wind their way over his shoulder and down to his arm. There's a gap, like they're still growing or something, and then down his right forearm are another mess of branches and leaves. He frowns, prodding at the tattoo with a wet finger, his jaw dropping as the branches move. Like, honest to fucking god, sways like there's a goddamn breeze on his skin or something.

"Stiles, you okay? Your heartbeat's going a mile a minute," Derek mutters, knocking on the door.

"Yeah... No... I don't know. D'you have any books on tattoos? Magical ones?" Stiles asks, loosely drying off his hands on a towel before he opens the bathroom door, twisting his arm in the morning light to get a better look at it.

"Not here; in the vault, maybe," Derek replies, blinking at Stiles' tattoo in surprise.

"Okay. Breakfast first," he replies, wiping his damp hands on his pants.

"You're not worried about that? It?"

"I'd be less worried with a full stomach," Stiles points out, smirking a little, then he frowns and grabs Derek, turning him around. "Holy fuck. I'm so sorry, dude. I had no idea. Shit."

"What?" Derek asks, trying to look over his shoulder unsuccessfully.

Stiles winces and guides him into the bathroom. "I uh, kinda tried to do some healing magic thing last night, and ... well, it must've transferred to you or something, 'cause... Just take a look, okay? And don't kill me," Stiles adds quickly, stepping back, hands raised.

Derek turns, his back facing the mirror, and moves so he can see what the hell Stiles is talking about. His eyebrows raise in surprise. The top spiral of his triskelion has spread out into what looks like hundreds of smaller spirals, reaching over his shoulders. His triskelion has multiplied itself over and over, and Derek doesn't really know how to respond to that. Stiles still looks like he's afraid Derek will tear his throat out with his teeth.

"Guess we'd better get to the vault sooner rather than later," Derek says with a small sigh.

"Breakfast burrito it is," Stiles says, giving him a quick grin as he runs off to get his shirt.

By the time they make it to the vault (Stiles ate two burritos because getting a tattoo and then healing it overnight is tiring - stop looking at me like that, Derek!), Stiles' tattoo has actually started branching off, completing the circuit up his arm, over his shoulder, and to the large tree on the back; his left arm is starting to show as well, a few branches darkening along his veins and pale skin. Derek has to concentrate so he won't stare at Stiles' forearms instead of the road, and almost skids off the road when Stiles grabs his shirt and tugs it aside to check the triskelions.

"Looks like they're slowing down. They don't look too bad, honestly. I'm gonna look like some weird tree fetishist or something," Stiles laments.

"I don't think a tree fetishist is a thing. And if it is, I don't want to know about it," Derek adds quickly when Stiles opens his mouth. "But they don't look bad," he adds, a bit softer.

"Thanks. I think it's got something to do with my power. Hopefully not the Nemeton," Stiles mutters, running a finger down one of the dark branches.

"Let's hope not," Derek agrees, pulling into the school and turning off the ignition.

Stiles kind of falls out of the car with all of his usual grace, and Derek shakes his head as he follows him down to the vault's entrance. The book isn't hard to find, especially when Stiles' arm actually starts to fucking glow when he's near it, and they spend a few hours reading through it to get a better understanding of what's happening to both of them. Stiles was right about his power; it's physically manifesting and will provide protection, and they're both thankful that it's nothing to do with the Nemeton. Derek enquires about his own tattoo, and Stiles reddens slightly as he mumbles something under his breath that not even Derek's werewolf hearing catches.

"What did you say, Stiles?" Derek asks with a frown. "Stiles? What did you do."

"Like I said, a healing spell. I... I touched your tattoo, and I felt it."

Derek feels a cold wave flow over him. "Felt what?" he asks hollowly.

"Your emotions. What you felt when you got the tattoo, what you're still feeling, I don't know, but ... dude, it wasn't your fault. You know that, right?"

"Get out."

"What? No, I was... I was trying to do something good, to help you! You can't tell me that you don't feel better! You've smiled today, Derek, and I haven't seen you smile in ... fuck, I don't even know how long. I just, I wanted you to feel something other than all of that guilt. I honestly didn't know it'd do that to your triskelion," Stiles babbles.

"Stiles. Shut up. Just shut up," Derek snarls and he hates to admit it, but he does feel ... well, not better, the guilt's still there - but he feels lighter, like maybe it's not all his fault, and maybe he doesn't have to carry all of this guilt for the rest of his life.

"I... yeah. Sorry, I'll just go. Uh, I'll call someone to pick me up, and yeah, you don't have to worry about seeing me anymore. I'll leave you alone," Stiles murmurs, and he sounds so forlorn and remorseful that Derek can't help but catch his wrist before he leaves.

He touches Stiles' tattoo when he grabs him, and Derek gasps as Stiles' emotions overwhelms him - remorse, anger, regret, fear, fear, fear (to disappoint, to revert back, to become the nogitsune again, to lose control, to lose his friends, his family, his pack, Derek), love... He lets go abruptly, clenches his jaw and just tries to breathe.

"Derek? Are you okay? Fuck, what happened?"

"We're even now," Derek replies, exhaling slowly.

Stiles frowns, blinking. "What?"

"You felt my feelings, I felt yours. So we're even. Now, help me find a way to get my tattoo back to normal," Derek mutters, turning back to the book.

Stiles gnaws his lip anxiously, obviously still concerned that Derek's going to seek retribution, but moves beside Derek a moment later, eyes scanning the page. He touches Derek's back gently, hand resting between his shoulder blades as he pats him in what he hopes is a comforting gesture. Stiles notices that the tattoo on his left forearm starts growing faster at the contact and pulls away quickly. That's something that can be dealt with another day.

...

End of second chapter.

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