A/N: This is my first (and probably only) take on the 2k7 movieverse. It may look fragmented, because it was written in very small chunks as an answer to a prompt on tf-kink meme.

Surprisingly, it's not AU. (At least until the next movie...)

Warning: you're at the edge of the fandom. Here, there be slash!

Megatron stalked through the corridors, the expression on his face guaranteeing any Decepticon that crossed his path to turn heel and flee for safety. Megatron snorted contemptuously seeing the tip of Scorponok's tail disappearing round the far corner. It wasn't as if he was in that bad a mood. It wasn't as if he'd killed any of the fraggers even if he was.
It was a very calming stress relief, true, but then he'd have to go to all the trouble of piecing them back together and reviving them just to get his damn spark to shut up. As if answering his thoughts, his spark sang quietly - the gentle, high pitched sound only ever heard by few - reminding him that there was one more mech nearby he hadn't revived yet.
"Oh, quiet you," Megatron growled. It was embarrassing, being reduced to arguing with one's own spark.

When he first realized that - irony of ironies - the Witwicky human, instead of destroying him, had accidentally handed him the allspark on a platter, he mused that perhaps he might even not kill the little rat when he sees him again. He'd been rather miffed to discover that his rare merciful intent was wasted, because Samuel Witwicky had been dead for over three hundred years now.

As the time progressed, Megatron started entertaining the idea of tracking down his descendants and squishing them to marmalade, because the allspark energy siphoning through his spark was such a freaking nuisance.

The most powerful source of energy in the universe his aft! All it was good for was detecting damaged mechs in his vicinity and giving him headaches until they were operational again.
Oh, and apparently it was a good beacon for humans searching for energy sources. The expedition that forty years ago had retrieved Megatron and his minions from the depths of ocean was a desperate, last ditch attempt of European Union to solve the energy crisis that plagued the humanity. They picked up 'a promising reading' and scrapped the rest of their resources to send a team down the cold depths. The team found the remains of supposedly dead Cybertronians, brought them to the nearby underwater base and made a mistake of poking around in Megatron's chest. The European Union never heard from them again.

Megatron scowled at the memory. Disgusting little creatures crawling all over his circuitry, yuck! And it took him forever to wash the sticky remnants away.
A soft chirp of the allspark interrupted his thoughts again, and with a frustrated growl Megatron turned sharply and headed to the repair shop. He ignored several humans jumping to attention upon his presence.

"Status report," he barked, only a moment later realizing he was speaking to an empty room. He didn't count the limp form on the table, because it couldn't respond for the obvious reasons. Making an exasperated noise, Megatron moved to check the readings on the monitor, when a trembling voice started a report.

"Sir, the external structure is one hundred percent operational, sir, the fuel systems are nearing eighty percent, sir, and neural wiring should be ready for a test run in next ten solar cycles, sir."

Megatron focused his gaze on the human standing on the dead mech's chest, and considered flicking him through the wall for the audacity of speaking to him. The allspark wouldn't react to human's demise (thankfully!).
But:

a) the human spoke in responce to Megatron's demand,

and b) judging by the colors of his uniform, it was one of Scavenger's pests. Scavenger arrived on the planet some two centuries ago, and had gone so completely native, that he knew his humans by name. He'd be terribly upset to have one of them killed, and the allspark would pick up at that, and then Megatron would have another headache. And no means of easing it too, seeing as giving Scavenger a replacement pet wouldn't calm him down. The silly mech cared for individuals, not numbers.

Not for the first time Megatron cursed Barricade for starting the tradition of brining pet humans home. Blackout was the only one not to join in the craze, but that was mostly thank to the fact that he already had a pet. Megatron had to personally go to the desert and retrieve the barely functional drone to stop Blackout's sulking and subsequent migraines.

The ultimate energy source, bah! Several million years wasted in pursuit after an upset-o-meter.
And if humoring his soldiers wasn't bad enough, now he was being forced to repair an all-damned Autobot! And no, dumping the carcass somewhere far away wasn't a solution. Once the allspark detected a Cybertronian in need, it wouldn't stop until Megatron got it operational. And then keep it in this state.
No, he wouldn't be allowed the pleasure of torturing the Autobot once it was back on-line. Not unless he wanted to endure even worse pain than the one he inflicted.
His spark chirped its annoying chirp again.
"Shut it! He's not even repaired yet," Megatron growled in Cybertronish, and left the room, not sparing another glance to the off-line body of Autobot known as Jazz.

PS. Oh, by the way, the prompt was:

"[...revived!Jazz x Megatron...] I'd like to see Jazz dealing with some serious physical fear, given that, after all, Megatron actually ripped him in half. Maybe a flashback, maybe a major freak-out. Bonus if it occurs in the middle of sex/close physical encounter. "