A/N: Just a short musing fic that came to me the night after I saw the movie. It's not my most thoughtful piece, but I needed to get it out there.
Starscream was used to Megatron being rough. Someone can't walk around with half a head and not be a rough customer. He stopped at nothing to achieve his goal, squishing the humans like vermin and treating the allied Autobots the same way. Megatron had no pity for his own troops, either. Starscream had woken up in the repair bay many times after failed missions. But Megatron, though brutally rough, had never bothered to go after any of Starscream's more sensitive components. He just walloped away on every outside part of Starscream he could reach until the seeker went offline, which was painful enough for Starscream. There couldn't be anything worse than that.
This sometimes made Starscream wonder why Megatron didn't just kill him. It wasn't like Starscream's penchant for treachery was a secret. Were Decepticons really so scarce that Starscream was a necessity? Probably not. The scarcity of seekers, then? No, again. Maybe Megatron just wouldn't bother to kill Starscream unless he did something incredibly drastic to challenge Megatron's power. Like, anything that half-way worked. That was most likely it. Megatron certainly would miss Starscream if he were gone, or do anything to stop his passing.
However, both of Starscream's beliefs about pain and about Megatron were tested when it came time to fight those nasty little fleshy humans in Chicago. Starscream was able to go up against the little humans unafraid of pain, thinking the kind the Megatron dished out was the worst that there was. He was wrong. It wasn't their little bullets or even small explosives that broke him. He had experienced those before and they were woefully inadequate to take on such a masterful example of Cypertronian machinery as himself. No, he was soldiering along fine until that brash little human (How in the Pit was he still alive anyway? And how did he keep showing up everywhere?) went for his optics with a weapon that was obviously Cybertronian in nature (And how in the fragging Pit did he get that?). At that point, Starscream lost any of his higher though processes and tactical intelligence. Or anything beyond the ability to scream and swat at the human like a human would a wasp, willing to do anything as long as the pain would just stop. He destroyed everything between himself and the human until another one of those persistent pests (Just how resilient were these things, anyway?) jabbed him in the other optic. "I can't see! I can't see!" Now the real panic set in. Optics were a seeker's second most important feature, besides the wings of course. A blind seeker was a grounded seeker, and a grounded seeker was a useless mass of nervous, destructive energy. Starscream was running around like a chicken with its head cut off (to use one of those insect's metaphors) until the second thing the humans had shoved in his optic exploded, and then he really didn't have a head.
Decepticons were always about iffy about any sort of afterlife. Sure they referred to "the Pit" or even sometimes the Well of All Sparks in slang, but nobody really believed that. So when Starscream regained awareness after having his head blown off, he was very much surprised to be in a dark place, faintly lit with glowing blue orbs.
"The Well of All Sparks…?" he whispered hesitantly. Perhaps it did exist after all…
His heavenly vision was interrupted by a sharp whack that brought him back to reality. "Hardly," growled the voice of the being that had hit him. Starscream looked around and saw that he was in the ruins of an old ship running on emergency power. Hence the round blue lights.
"M-Megatron?" Starscream ashamedly stuttered. "But how am I alive?"
"Although the insects thought you could do better without that mass of useless circuits you call a head, your spark was undamaged. Though I would have preferred to let you lie, the Decepticons always need troops."
So there was Starscream's answer, but somehow, he still wasn't satisfied. He knew Megatron wasn't keeping him alive out of some sort of twisted romantic attachment to the seeker, but it wasn't just from a personnel need, either. No, Starscream thought, it was some sort of weird symbiosis. Megatron needed Starscream because the seeker's constant attempts at treachery kept the Decepticon leader on his toes, and his sycophantic groveling whenever he was caught puffed up Megatron's ego a bit. And Starscream needed Megatron because, as much as the seeker could never admit it, even to himself, he secretly knew he really wasn't programmed to be a leader. He was a good second and an especially good wing commander, but charismatic leadership skills just didn't fall to him.
As Starscream picked himself up and examined his new head (as hurriedly cobbled together as it was, it was still better than nothing), he considered how this new revelation would affect his working relationship with Megatron. Not much, he thought, and followed down the corridor after his leader.