Disclaimer: How to Train Your Dragon belongs to Dreamworks, not me.

She was thirteen when her soulmate mark appeared.

It was a relief and a nuisance to be honest. A relief because she didn't have to keep worrying about "when is it going to show up?" and a nuisance because every other girl in her class kept fussing over their marks and wondering who might have the one that matched. Honestly, Astrid wasn't concerned about that part. She'd meet her soulmate eventually, as the mark on her wrist clearly stated. There would be plenty of time.

She was fifteen when she met him.

She was walking home from school, trailing behind her brothers, mentally calculating how much time she would have to spend on her math homework if she wanted to get the first draft of her history essay done. Suddenly there was a screech of rubber on asphalt, a metal-on-metal shriek, the harsh crash of glass shattering. Astrid nearly jumped out of her shoes.

"What was that-" she started to say, but even as she turned she already knew. An SUV had taken the corner too sharply and ignored the stop sign, T-boning the silver sedan that should have had the right of way. The smaller car was crumpled like a discarded piece of paper in the intersection, broken glass spread out and sparkling in the afternoon sun like a small galaxy.

Her brothers dropped their backpacks and took off running. "Stay there, Astrid!" Bear shouted. She bent to pick up their backpacks, her hands shaking. Her brothers ran to the crash, Bear going to the truck and Finn to the sedan. She was grateful they were there. They were older and smarter, they could handle this.

"Az? Astrid!"

She snapped out of her daze and looked at Bear. "Call 911," he said. "Tell them to send help now."

"Okay, okay," she said, fumbling in her pocket. She sank down on the curb, making a barrier of backpacks, and dialed the number with shaking fingers. Her voice sounded remarkably calm as she talked to the dispatcher, but she kind of wanted to add a this is my first 911 call, by the way. It seemed like a rite of passage that she wasn't ready for.

"Az, can you come over here?"

She looked up at Finn. Do I have to? she wanted to say, but mechanically she stood up, her phone clutched in her hand, and edged closer to the sedan. Her oldest brother stood by the crunched hood of the car, his football jersey smeared with something dark. Oil, she hoped.

"Az, I need you to help me," Finn said. He kept his voice low, like he was coaching her on a layup while they played basketball in the driveway. "This is going to be rough, but I need you."

Her mouth went dry. "What is it?" she asked.

"There's two people in the car," Finn said. "There's a kid your age. I need you to stay with him, okay? Keep him awake and talking till help gets here."

She was shaking. "Sure," she said, picking her way around the shattered glass towards the passenger side of the car. She could catch just the slightest glimpse of dark red hair through the remains of the window.

The boy still buckled into the passenger seat was small and slight. His chin tipped forward to rest against his chest, and blood trickled in a thin line down his chin and dripped on his shirt. Astrid crept a little closer and nearly leaped out of her skin when his eyes opened sluggishly.

"Hey," he drawled, his mouth screwing up in confusion.

"Hi," she said. "Hi, are you okay?"

She instantly regretted it. His face was bloodied and the car was practically folded in half, of course he wasn't okay.

"What happened?" he mumbled.

"You were in a really bad car accident," Astrid said. "We've already called, help's coming."

He frowned slightly, his chest heaving once as he struggled to process that information. "Am I okay?" he asked, his voice thick.

"I don't know," Astrid said. She shifted against the side of the car. "What's your name?"

He paused. "Hiccup," he said at last, as if he had to think about it.

"Hiccup?" Astrid repeated, wrinkling her nose.

"'s my nickname," he mumbled. His eyes were beginning to drift closed.

Astrid reached into the car and grabbed his hand. "Don't fall asleep," she warned. "How old are you?"

"Almost fifteen," Hiccup said. "My birthday's in February." He looked up at her sluggishly. "Who're you again?"

"Astrid Hofferson," she said. "And I'm fifteen. Just turned fifteen."

Hiccup's hand was cold and clammy in her grip, his fingers limp. Astrid squeezed hard. She tried to remember what she'd learned in health class about accident victims, but it was like someone had deleted that file in her brain. Keep him awake and keep him calm, that was all she could think. "You should talk to me," she said. "Tell me something about yourself. What's your favorite color?"

"Green," he said. He turned his head, wincing as he did. More blood dripped down his forehead. Astrid pulled the cuff of her hoodie sleeve over her palm and wiped it away from his temple and cheek. "And…I like Star Trek. And my dad is making me try out for soccer." His lashes fluttered for a moment; he opened his eyes and tried to focus on her face. His pupils were dilated. "What about you?"

"I run cross country and play basketball," she said. "My favorite color's blue, I've got two brothers and a dog."

He smiled a little. "What's his name?" he asked.

"Her name's Stormfly," Astrid said. "She's a greyhound."

"I've got a cat," Hiccup said. "Except…nobody knows about him. I've been hiding him in my old treehouse. But I sneak him inside a lot. Nobody's caught on yet."

The color was draining from his face, leaving his skin white and his freckles almost black. "What's his name?" Astrid asked, squeezing his hand again, his fingers feeling more and more lifeless.

"Toothless," Hiccup said. He took a deep shuddering breath. "Where's my mom? Is she okay?"

Astrid's heart sank. She couldn't see the driver very clearly from the way the car was crunched, but from what she could tell…it didn't look good. "Your mom's going to be okay," she lied.

Hiccup took another shuddering breath, this one shallow and rattling in his thin chest. "I want my mom," he whispered.

Astrid's heart did another unnerving flipflop. She didn't blame him; she'd want her mom too. But from the stillness in the driver's seat, and the fact that Finn wasn't talking to the the woman sitting there…

Astrid fumbled for the door handle, her other hand still holding Hiccup's. Mercifully it opened, although she had to jiggle the handle and lift the door up before it would. She let go of Hiccup's hand and sat down on the edge of the seat, facing him. "You're going to be okay," she said.

She hugged him gingerly, unsure of his injuries but wanting to reassure him. He was cold all over, his body beginning to shiver. He didn't say anything, just rested his chin on her shoulder. His uneven breathing echoed in her ear like a ricochet.

"My leg hurts," he whispered.

Astrid leaned back. "Why didn't you say something?" she said.

She looked down and realized Hiccup's left leg was pinned between the center console and the dashboard. The front of the car had been smashed so far forward that his leg was crushed between them. With sickening horror she realized that blood was soaking through the fabric of his jeans, turning it nearly black.

"Oh my god, why didn't you say something?" she said, her voice rising. She scrambled to her feet. "Finn! Finn!"

Her oldest brother ran around the side of the car. "What's wrong?" he demanded.

"He's bleeding really badly," Astrid said. "I didn't know, he didn't say anything."

Finn pushed past her to look into the car and swore when he saw the blood pooling on the floormat. "You have something I can use for a tourniquet?" he said.

Astrid ripped the ribbon headband out of her hair and handed it to him wordlessly. Finn crawled into the car to tie it around Hiccup's leg.

"Astrid?"

It was so faint she barely heard it. She looked down at Hiccup. His eyes were hazy, the pupils dilated. "Can you stay with me?" he whispered.

Astrid nodded, sinking down beside him. He was shaking, his lips pressed together tightly. She took both of his hands in hers, rubbing her thumbs across his knuckles. "It's okay," she whispered. "It's okay."

Hiccup didn't seem to hear her. Sirens were echoing now, faint and growing louder. "Just hold on," she said.

His head tilted forward and he slumped over the restraint of his seatbelt, his forehead falling to Astrid's shoulder. She caught her breath and pressed her thumbs against his wrists, feeling for a pulse.

The pulse was there, faint and thready, and she looked down at his hands in relief. His skin was white, the veins blue, but there was a black mark on his right wrist. His soulmate mark. A straight line with two interconnected half circles.

The same mark as hers.

Author's Notes:

WELP.

I've never written a soulmate AU, so here it is.

There's probably going to be a followup, I think? I've been writing a lot of these little prompted drabbles and having a good time with it. I've got the mermaid one too, that one is probably going to get a second chapter. There's a couple more on my tumblr (themetaphorgirl) that probably will just stay there and stand on their own.

But yeah! Let me know what you think!

(Also, I've completed a canon oneshot involving Hiccup and Astrid finally declaring their love. It involves seasickness, the "two truths and a lie" game, and Astrid being fiendishly clever. Anyone wanting to see that one?)