It is common knowledge that some part of Claudia's family had magic abilities, but Claudia hadn't inherited them herself so they didn't expect Stiles to either.

If nurtured with it, Stiles could have had his powers for years, but since he hadn't he had to endure the terrible ordeal of his powers making themselves known on his tenth birthday.

"When will be wake up?" Derek asks Claudia's mother when she comes back in the room later on.
"Soon, that's why I'm keeping everyone away you should be with him when he wakes up. He'll be scared and confused so you need to keep him calm. Can you do that?"
"Yeah, okay," Derek agrees.
"I'll talk to Stiles about mates. All us supernaturals have them and you two are each other's. Does he know?"
"No," Derek mumbles. "I didn't want him to make the wrong decision because it was me. I'll tell him when he's older."
"Okay. That's okay, I'll explain what they are but let you two work it out."

When Stiles wakes up he starts to shake, looking around frantically until he sees Derek.
"Hey, it's okay," Derek soothes, smiling sadly when Stiles clings to him and starts crying again. "I know, love. Gave us a real scare there. But you're okay. I've got you. Do you feel okay?"
"Tired," Stiles shrugs and wipes at his eyes. "A little sore."

Derek helps him sit up and pulls him into his lap. Stiles sighs, closing his eyes and resting his head on Derek's chest.
"Thank you," Stiles whispers. "For looking after me."
"I'll always look after you, Gem. Want me to go get your Mum?"
"No, stay!" Stiles says quickly. "Please."
"Okay, love. Dad? Gem is awake."

Claudia appears in the doorway with John, cheeks red and tear stained.
"Hi, baby. You okay?" Claudia asks as she comes and sits beside him.

"I'm going to go, just to the kitchen," Derek tells them and tries to detach from Stiles.
"Don't leave me please," Stiles sniffles.
"You can cuddle with your mum and dad. I'm only going to get a drink. I'll be back in a minute."
"Promise?" Stiles asks.
"Promise," Derek smiles and loops his pinky finger around Stiles'.

Andrew and Talia pull Derek into a comforting hug when he walks into the back room. Talia kisses his head and strokes his hair while Andrew rubs his back. Laura shuffles over, ruffling his hair before nuzzling him and slipping under her mum's arm. Cora follows and tugs Adam along to press in around Derek.

"I was so scared," Derek sobs. "I'm so happy he's okay. I need to tell him. I can't- I can't keep it a secret. What if it happens again? I can't not have him know."

"Babe, your emotions are everywhere right now. That's a big decision to make, which you're better making when your heads clear. How bout you come for a run?"
"I promised Stiles I'd stay," Derek sighs and scrubs at his eyes. "C-can we have a pack night?"
"Just us or the rest of them?"
"Just us," Derek replies quickly. Andrew smiles sadly and kisses his temple.
"No problem, bud. Now, you go and cuddle Stiles a little longer before we leave."

Stiles pouts when Derek comes back into the room.
"Why are you sad, Der? Gran just told me I have magic powers!"
"I'm going home in a bit, but I want some cuddles before I leave. Then you can tell me about magic powers. Okay?" Derek asks and musters up a smile.

Stiles clambers into his lap and wraps himself around him.
"So Gran said she made me better but I was sick because we didn't know I had powers. And then she said that I have a soulmate. Someone that I'll fall in love with and have kids with and be with forever."
"Wolves have that too, Gem. It's cool isn't it?" Derek chuckles at Stiles' excited ramblings.
"I wish you were my soulmate," Stiles sighs and kisses Derek's cheek softly. Derek bites his lip and closes his eyes to stop himself crying.
"Me too, Gem. Me too."

When they get home Laura and their dad go into the preserve, setting up the tent and fire they have for pack nights.

Talia makes some hot chocolate in a thermos to keep out there with Cora while Derek and Adam get sleeping bags and everybody a spare change of clothes.

Adam nudges Derek as they walk up to where the tent is.
"It'll be okay. He's not going to leave you."
"I don't want him to have to choose or feel pressured, especially now. But by the time he's eighteen I'll be twenty three," Derek sighs.
"People find their soulmates when they're a lot older than twenty three, Der," Adam argues.
"I know- I just. I wish it wasn't this difficult."

"I know. Hey, when you're twenty three I'll be twenty seven. Stop making me feel old. I'm already nineteen," Adam jokes.
"Hey, you feel how you are. Are you in uni this week?"
"Yeah. Two and a half more years and I'll be a nurse, come back here and work at the hospital. I'm home for weekends and holidays, you can call me whenever you want. Maybe if things are tough you could stay with me for a little while."
"I'd like that," Derek smiles.

---

Derek spends a bit of time away from Stiles to gather his thoughts. Then everything goes back to normal and Stiles is just as cuddly as ever.

They spend less time together because Stiles has to practice keeping his magic under control so he doesn't hurt anybody but his lessons go well and he's allowed to relax a little more.

On his eleventh birthday Stiles drags Derek along to see his cake. Everybody is bustling about to get the food ready, but nobody bothers Stiles and Derek.

"Go on, then," Derek grins.
"Watch."

Stiles concentrates for a moment, forgetting that his hand is still in Derek's. His hands glow bright and a spark flies out to light the candles on his cake.

Derek yells, pulling away and writhing in pain as the skin on his hand begins to sizzle away and reveal the muscles underneath.

"Gran!" Stiles screams, sobbing as he holds his hands close to himself so he doesn't hurt anybody else.

Everyone rushes in, Stiles' gran murmuring as Andrew takes the pain. Stiles cowers in the corner, crying while his mum tries to calm him down.

"Why isn't he healing?" Stiles wails.
"Its magic, it hurt them more."

Stiles doesn't talk much after that, just clings to Derek and nods or shakes his head. Derek assures him it's fine, he hurt himself all the time when he was learning to control his shifting. But Stiles is adamant that everything is his fault and he is terrible. He even wears gloves so he doesn't touch anybody directly.

They put up with it for nearly a year before they decide that change would help him and he should go and stay in Poland for a little while.

He stays in time for his twelfth birthday, but leaves a few weeks afterwards.

Derek's body is wracked with sobs, heaving and loud, when he says goodbye to Stiles.
"Gem, it's not your fault. You've got your phone now so you can message me whenever you want. Maybe I can come visit sometime?"
"Please. Der, I don't want to," Stiles pleads.
"Not for long, love. You'll be back before you know it. And you will be able to control your magic better and maybe even speak polish better. You always told me you wanted to learn again," Derek soothes, rubbing his cheek on Stiles' head.
"Yeah. I can teach you? Help you learn too so it's easy for when you come visit?"
"That sounds amazing, Gem. You'll be okay. Your mum is with you and your dad will be with you soon. I love you, Gem."
"I love you, Der."

---

They message each other everyday, Stiles flying home for Derek's birthday and the other way around.

Both boys learn polish together and Stiles tells him everyday about what he's learning to do and how school is and how his other friends are.

It's difficult. The boys have never been apart and now they're separated for who knows how long.

Stiles really matures out in Poland, having to stand on his own two feet.

When Derek next sees him in person he is home from from his first term of university. He is studying to be a history teacher, which he's always done well with in school. Stiles let's him rant about lecturers and smiles in all the right places, knows just what to say to make him feel better.

Derek's mum has her hands over his eyes, guiding him into the living room carefully.

"Okay. Open."

"Happy birthday to you!"

The song continues being sung but Derek feels like his heart has stopped. Stiles is stood there, broadened out a little and a lot taller since the last time he saw him. Claudia beams at him over his shoulder and John smiles proudly. His siblings surround them and his dad comes over to ruffle his hair.

Derek smiles so hard he's scared his face will split in two when Stiles lights the candles on the cake with a flick of his wrist. He starts laughing as he blows them out and quickly stumbles forward to haul Stiles into anhug.

"Oh my god, I've missed you so much. Holy shit. You're here!" Derek exclaims, squeezing him tight. Stiles chuckles and nods.
"You give the best cuddles. I've missed them while I was away."

Stiles' voice is surprisingly deep when he talks, grinning at Derek like he's the fucking sun.

It takes all of Derek's strength to not kiss him then and there. He laughs until he cries and has to wipe his eyes because he's so happy to see him.
"Oh Der," Stiles laughs sadly. "It's okay."
"When are oh going back?"
"If you want to come on holiday next year, I'll go then?"

Derek pulls back, examining Stiles.
"Seriously?"
"Seriously. I'm back for good."

Derek cries for a good half an hour and doesn't let Stiles leave his side, even when Laura teases him and sends him a silly wink.

---

On Stiles' fifteenth birthday he confuses the hell out of Derek by handing him a card. Derek has stayed at his house for his birthday for fifteen years now and nothing has stopped the tradition yet.

"Gem, you do realise this is meant to be the other way around?" Derek chuckles, but he opens the card anyway.
"Just read it, doof." 

He lets his eyes flit from word to word. In Stiles' handwriting which he knows well is:

To Derek.

I know we're soulmates.

Lots of love, your Gem.