Here's just a random little oneshot I've had in my ideas folder for a long time now and threw together just now because I need a break from a) school b) revision and c) writing my main story. Title taken from the short story Born To Endless Night.

Disclaimer: I don't own TMI.

"Jace," Alec said loudly, backing hastily away from the demon standing in front of him, "what is that?"

It was massive. It would've been dangerous enough with its hard, green-and-yellow scales, unnaturally blue eyes, and a forked tongue that flicked out, tasting the air, but its size alone made it a formidable opponent. It was at least twice as long as Alec was tall, with the thick torso of a lizard. He doubted that if he (for some absurd reason) hugged the tail, his hands wouldn't meet each other on the other side.

But that wasn't the reason he was so annoyed.

The reasons he was annoyed were situation on the lizard's back. Muscular, iridescent, sinewy: its wings were rather hard to miss, even in the dim light of the sewer. Meaning. . .

"Isn't this familiar?" his parabatai drawled behind him. "I hope you don't try to pull the 'you said they were extinct' card again. That's a one-off trick."

"I know perfectly well dragon demons are only nearly extinct," he snapped back. "I still have the scars from last time to remind me." He narrowed his eyes at the demon, which was approaching him slowly and steadily. He drew back again, and nocked an arrow in his bow.

He drew back the string, world narrowing to this moment, this shot, the chink in its armoured scales he could see, just between its shoulder blades. . .

And then Jace was in front of him again. Alec sighed irritably and lowered his bow; he couldn't shoot now, not without hitting him. And what was he doing?

He voiced the question aloud. "What are you doing?"

Last time, they'd taken it out slowly but effectively. It had been gruelling work, hacking away at its scales again and again until they gave under their runed blades. So why, by all the angels, had Jace seen fit to jump onto the thing's neck and start riding it like a rocking horse?

He didn't understand his parabatai sometimes. He doubted anyone did.

The demon didn't seem to like that Jace was on its back, but it was an especially stupid one; it couldn't throw him off. It bucked, back and forth, left and right, but Jace had the blessing of angel blood and it was only a lesser demon. He held on.

"Jace. . ." Alec warned, then the dragon demon let out a loud skree and threw its head backwards, as if suddenly remembering - at the same time Jace did, judging by the flash of panic that crossed his face - that it could breathe fire.

And it did. Violent blue and orange flames belched from its throat, torching the sewer wall. Alec rolled aside, off the pile of. . . excrement. . . he'd been standing on, just as the wall beside it glowed red and the pile itself was set aflame.

There was a bang as the gas in the tunnel ignited, and Alec was thrown to the ground, whacking his head on the floor, vision going blurry.

His hand went to his scalp; it was sticky with blood; pain shot through when he touched it. That'll need an iratze. . . he had the time to think, before he was up again.

Jace was still holding on.

"Alec!" he shouted. "Grab your bow! Shoot it!"

"My shots won't penetrate its hide!" he shouted back. The blast seemed to have burned all the oxygen from the surroundings; he was finding it difficult to breathe, his heartbeat coming quick and fast.

"I'm going to drag it round." Jace sounded so exhausted that Alec highly doubted the feasibility of that statement, but he held his tongue. Jace was a miracle worker - that is, he seemed blessed with an inordinate amount of good luck for the amount of reckless shit he got up to. "Get ready to shoot it through the eye. Dragon demons have brains, right? That should kill it."

Right. They did.

At least, Alec thought they had brains.

He was pretty sure. . .

He scrabbled around among the waste for where he'd dropped his bow. The arrow he'd been holding was long gone, but his quiver was still on his back, and one shot was all he needed.

One shot was all he got.

Thankfully, his skill didn't falter; the arrow soared straight through the demon's eye and into its head. It let out a piercing skree again before it began to disintegrate into nothing.

Jace was barely onto his feet by the time Alec punched him in the shoulder.

"You - reckless - idiot!"

Jace scowled, rubbing the injured arm. "It worked, didn't it?"

Alec shook his head. "Why are you the way that you are? I just don't know what o do with you sometimes." He glanced down at himself, at the burnt holes in his gear (and the excrement covering it), then smirked. "And since I'm going straight back to my and Magnus's place to look after Max, you get to explain this to Mom."

From Jace's face, Alec gathered he would've preferred to face another dragon demon.