a/n: I'm hardly the first person to speculate on Sunstreaker's whereabouts during the Bayverse trilogy, and I'm quite certain that this idea has been done before. I've never read one, but I'm fairly certain I can't be the only one who thought of it. Still, it's an idea worth pursuing and I'm quite fond of this piece.

Please enjoy.

Title: Incomplete

Universe: Bayverse, pre-2007

Characters: Sunstreaker, Thundercracker, Skywarp

Rated: T

Warning: AU-ish, speculation

Description: Becoming a Decepticon is by far the most Autobot action Sunstreaker has ever taken.

It's too easy to be a Decepticon, and sometimes, Sunstreaker worries that it'll stop being a game for him. That it'll stop being pretend and it'll someday be real. It's harder now especially, since Sideswipe is nowhere near. Not even in the solar system as a matter of fact. Their bond is stretched thin, to the point it's almost transparent. To the point that if it were possible, Sunstreaker fears it would snap in two, leaving him alone.

Sometimes, Sunstreaker can hear the echoes of what his twin is feeling. He catches a loud exclamation or a pang of loneliness or a moment of obnoxious triumph. But those are few and far between. And sometimes, it's better to ignore them, too. Better not to have that distraction.

It was hard, at first, being separated from his twin. Having to think without Sideswipe resonating inside him. Having to act when he's just "Sunstreaker" and not "Sideswipe and Sunstreaker." The Decepticons like to remind him that he's been abandoned sometimes, that someday, he'll have to meet his brother on the battlefield. They like to test his loyalty, see if he's truly a part of their cause. Whatever their cause is.

After all this time, Sunstreaker's pretty sure they've all forgotten what started the war, despite having perfect memory.

It's supposed to be a good thing he's doing. The perfect eye on the inside. The Autobots always thought he'd be a Decepticon anyway. He didn't have what it took. He wasn't honorable or soft-hearted enough. They always stared, wondering why he was fighting for the wrong side. They figured that if not for Sideswipe he'd have long defected.

It's too easy to be a Decepticon, and maybe that's his problem. He's here, by his own choice, but not because he's turned his back on Prime and Sideswipe. It's because this is the only way for them to win, for Sideswipe to survive, for this war to end before any more of their civilization turns to ash. Cybertron is already gone. Sunstreaker couldn't bear it if Sideswipe were gone, too.

So here he is, sitting in a Decepticon stronghold, drinking some of the lowest grade energon that's ever passed over his glossa. He's sitting shoulder to shoulder with Thundercracker and Skywarp, listening to the latter bitch about Starscream while the former quietly sips his own poor grade energon. Might as well be an Autobot, that one, and maybe he is, maybe he isn't. Sunstreaker hasn't gotten close enough to tell.

He's here, instead of with Sideswipe on Earth, because here is important. And while the two Seekers are a poor substitute for the hole inside of him where Sideswipe should be, they'll do for now. So long as it keeps Sideswipe safe.

And it occurs to him that becoming a Decepticon is by far the most Autobot decision Sunstreaker has ever made.

a/n: Sideswipe and Sunstreaker (and Ratchet) are my absolute favorite Transformers (with Soundwave coming in right at their heels along with Vortex and the triplechangers) so expect to see more of them.

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