A/n: This is movielover48's idea. It's also the first chapter not loaded from my laptop. This is, of course, very interesting news that you are all amazed to hear.

Thunder boomed overhead, followed instantly by a blue flash. The electric colour came from a dragon's blast rather than lightning, but the next flash was due to the other force of nature.

Hiccup yelled in exhilaration as Toothless dived through the storm clouds. He was glad he hadn't listened to Astrid's warning; she made a good point, but nothing came close to the feeling of dodging lightning in an otherwise pitch black sky while the rain pounded on your back.

"Just one more dive and we'll go back," Hiccup told Toothless. The equally thrill-seeking dragon nodded in agreement, slightly saddened to have his fun cut short but not wanting to stay out for too long lest Hiccup catch a cold.

With one last quick dip through the clouds - the water was no problem by now, given that they were already soaked to the bone - the pair set their course to the village. The storm was one just above Berk, so the journey didn't take too long.

Hiccup landed just in front of Astrid's open door. "See, told you it'd be fine," he said, slightly smugly. Astrid opened her mouth to reply, but didn't get that far.

A flash across the sky not previously announced by the customary clap of thunder interrupted her. The light was blinding, and she stumbled back into her doorframe. When the dark spots in her vision finally faded, she looked back out into the rain to see two slumped figures on the floor.

"Hiccup!"

Astrid sat in wait of Hiccup and Toothless's return to consciousness. She'd dragged the two inside as soon as she calmed down, then gone off to fetch something to dry them with.

When she came back, she was confronted with a strange sight. She was certain that the second night fury - which had appeared without explanation - was Hiccup; it had a missing leg, and Hiccup's own modified prosthetic lay on the floor beside it.

The storm cleared not long after, and Astrid went out to explain the situation to Valka.

"Valka?" Astrid said, popping her head around the door.

"Yes?" Luckily, she was awake and waiting at the table already.

"It's about Hiccup," Astrid started. Valka frowned in concern and ushered the younger Viking to the table to let her tell her tale.

Hiccup woke with a start. It confused him; he had no idea why he jerked up with such force, or why he was breathing so heavily. It was because he was sorting out his strange panic - had he had a nightmare? - that it took so long for him to notice his other, slightly more pressing problem.

'I'm a night fury.' he deadpanned, only realising because he'd lifted a hand - now a paw - to rub his eyes. It wasn't his first time as a dragon, but it was the first time Toothless had also been one. And he was - Hiccup had checked that first, assuming it had just been a simple mind swap.

Ah, what a strange life he led.

'Toothless!' Hiccup hissed, glad that he already knew Dragonese - he mightn't have been able to understand himself otherwise - and hit his friend lightly.

'What?' the night fury by birth asked slowly, taking great effort in peeling his eyes open.

'I'm a night fury.'

'No...' Toothless mumbled, 'I'm a night fury. You're a... night fury?'

'Told you.' Hiccup smirked. 'Don't know why though. It's really weird...'

'You got that right...' Toothless said. 'But... how?'

'No idea. All I remember is... Actually, I don't remember anything.'

"Being hit by lightning can do that to you."

Hiccup turned round to face the person who'd spoke. 'Astrid?' he spluttered, 'When did you get here?'

"Well, it is my house." Astrid smiled. "Good to see you awake; it's been a few hours. So, you're a night fury now?"

'Yep. Just my luck. And it seems I can't speak Norse anymore; every time I try to do it, I end up speaking Dragonese.'

"What if you try to speak Dragonese?"

'Huh. I'll try...' Hiccup said. 'That work?'

"Nope." Astrid laughed. "Looks like no one's going to be able to understand you..."

'Just great...' Hiccup complained. 'How am I supposed to be a chief now?'

'How do you ever act as chief?' Toothless asked sarcastically, 'You're always getting into such weird situations.'

'Well, I'm sure I'll manage it. Can't be that hard, can it?'

'I jinxed it, didn't I?'

'Yep.' Toothless said, barely concealing his laughter. 'This is great. How did you even manage this?'

'This' was complete chaos in the village. The twins had decided that everything Hiccup said was an order to destroy things, and some people had actually been gullible enough to believe them, resulting in the fire that raged over half the village. Others didn't believe Astrid when she said that the new night fury was Hiccup, and they had sent out a search party to look for the 'missing' chief. Only the select few who could understand Dragonese knew what they were supposed to be doing, but there weren't enough of them to make a big difference.

'Need some help?' Toothless offered at last, finally getting over his mirth.

'Just a bit,' Hiccup responded, voice strained.

'Okay. Just wait here.' Toothless ordered. Hiccup frowned as the dragon flew off - where did he even have to go?

After hours of clean up work, Hiccup and Toothless slumped to the ground, finished.

'Thanks,' Hiccup said gratefully. Toothless had directed the dragons from the nest to help, and they'd managed to get the village back into order. Meanwhile, Astrid was directing the Vikings in Hiccup's stead.

'Go for a flight?' Toothless suggested.

'Yeah!' Hiccup grinned. 'Good thing I learnt how to last time.'

The two took off then, and Hiccup was glad to finally get off his feet. Though it was possible to hobble around on three feet, it was much easier to use both of his wings to carry himself around. That, and flying was just plain fun, no matter which part you were playing in the process.

Hiccup woke the next morning in his own bed. The first thing he checked was his species, and he was equally confused and relieved to discover that he was human once again. While being a dragon was fun, it was much more natural for him to be a human.

He let out a sigh of contentment, pleased to note that it was Norse that he now spoke in. He sat up, ready to start a much easier day of chiefing.

"Wait..."

His leg was still in Astrid's house.