It is said that the day Optimus Prime's Spark went offline for the second and final time, the entire world felt a shudder that shot cold tendrils of fear down every organic spine and caused the machines to pause in their courses.

Optimus's legs buckled and he fell to his knees before Sentinel. The acid rust had struck him directly in the center of his chest, burning through his armored plates and causing his Spark chamber to cave in on itself, snuffing the life-giving bolt within. It was so fast that he didn't even have time to utter a single cry or farewell. He simply knelt there, staring lifelessly down at his own torso until the rust finished its job and his top half fell to one side, growing smaller and smaller as it dissolved into a pool.

Megatron stood frozen merely fifty meters away, the whine of his charging cannon dying. His intention had been to fire on Sentinel from behind and let Optimus take him on from the front, effectively sandwiching the renegade Prime between two dangerous foes. But now that plan was useless. And the strange pain his his own Spark troubled him. When he had "killed" Optimus before, he hadn't really killed him, merely put him in stasis lock in hopes that he would stay inert until the Fallen's plan could be carried out. The long-unused bond between them hadn't done this then. It was as if in his final moments, Optimus had broadcast something to his wayward brother, but the words hadn't made it, only a desperate and miserable feeling.

Sentinel turned to face the Decepticon and scoffed. "I should have known," he murmured, bring up the acid blaster.

But he never fired. Instead he turned his gaze skyward, emitting a howl of rage as he did so. The space bridge collapsed, turning into a vortex that reduced Cybertron's forlorn shape into a whirl of debris. Megatron could not contain the high, thin cry of protest that escaped his vocal processor, a whimper in the wake of Sentinel's roar.

The plan had failed. The plan had failed. Cybertron... gone. Gone forever. All that Megatron had worked for so carefully, all he had sacrificed, all the Sparks and souls he had terminated in the name of this most sacred goal... wasted. The fact that humans and the remaining Autobots might have been the culprits didn't reach Megatron as he quivered, no, quaked in white-hot fury. Before reason could creep its laborious way through the circuitry of his processors, he found himself lunging at Sentinel, taking advantage of the windbag's temporary distraction. He tore the long length of chain that adorned his torso off and used it to pin Sentinel's arms to his sides, all the while tearing at him with sharp claws. The chain snapped, its alloys about as useful as dental floss compared to Sentinel's strength, but that had also been a distraction. Megatron dove at Sentinel's legs, tripping him up, and then rose to catch Sentinel's blaster arm just as it raised the acid rust blaster in his direction.

And once Cybertron had perished, passed beyond all hope of restoration, the formerly triumphant Megatron chose to punish Sentinel Prime for the space bridge failure, and perhaps for bringing about Optimus's end.

It became a contest of sheer will between the two of them as the blaster wavered first toward Megatron's face, then toward Sentinel's. Servos screeched under the strain as they glared pure hatred at one another, all former alliances forgotten. "Your incompetence is to blame for this catastrophe, Megatron," Sentinel grunted derisively.

Megatron hissed as the muzzle of the acid blaster tipped dangerously close. "I have learned my lesson about foolish pride," he snarled. "It is time for you to learn yours."

That said, an explosion detonated on the outward side of Sentinel's blaster arm, a human mortar. Though similar projectiles were pelting the both of them, Megatron refused to relent. When Sentinel's arm gave a slight tremor from the pounding, Megatron pushed. Hard. The blaster went down, down so that its muzzle was pointed directly at Sentinel's nasal ridge. Megatron calculated his odds in a picosecond and then brought up his other hand around Sentinel's, forcing the trigger finger to squeeze.

A spray of acid rust caught the Prime squarely in the face. After that, the end came quickly. His limbs fell limply away as his head ceased to exist, and Megatron stepped back with the blaster in hand. He pumped out two more shots for fair measure, until all that remained of Sentinel Prime was an oozing puddle that emitted roils of smoke.

For a moment it was as if he had been shocked into temporary stasis. Explosions rocked around him, but he didn't hear or see them, though his frame felt the impacts. He looked down at the acid blaster in his claws and regarded it numbly as if it were something common like a wrench. Then he shuffled toward what little remained of Optimus. Something gleaming lay in the pool that had once been Optimus Prime, and Megatron's crimson eyes blazed as he realized what he beheld. The Matrix of Leadership.

Sentinel's demise assured, the Decepticon Commander took possession of the Matrix...

He picked up the shining silver dagger shape with precise care, as acid rust dripped off its curved exterior, unable to eat through its pure composition. He clenched it in his fist and wondered what he might be able to do with it. His gaze was then drawn back to the steaming pool that had been Optimus. For so long Megatron had dreamed of bringing about Optimus's final end, of course after waving the Decepticons' conquest of the universe in the Autobot's face. But now... now, he wished Prime were still alive. Now that Cybertron was gone, none of them had anything left to fight for. The object of their war had been ripped from them, and now they would struggle against the currents of its aftermath.

He heard humans shouting and screaming and perhaps wailing over Optimus's death (he was truly a god to them, more of a god than Sentinel or the Fallen could ever hope to be) and turned to regard them. Sam Witwicky and his female accomplice emerged from Bumblebee and clung to each other, liquid draining from their eyes as they mourned.

"Boy," Megatron rasped, and he knew Witwicky heard him because he gave a start despite his profound sorrow. "Come."

And Megatron stooped painfully on one knee, extending the hand that held the Matrix in the human child's direction.

And presented it to its first chosen bearer.

Sam came forward slowly, jerkily, shaking but resolute. Someone shouted for him to stay back, but his grief for Optimus overrode any sense of self-preservation he might have had. It occurred to Megatron that in this respect, Optimus and the boy were alike.

"Take it," he commanded, forcing the Matrix into the boy's small fleshy hands. Sam stared up at the metal titan, his eyes wide and red-rimmed and still leaking.

"Why?"

Megatron could not answer, not immediately. Instead he stood, though the act caused his battered gears to grind in warning. He took a few strides away from the boy and primed the acid blaster. "Because there is nothing left for me in this world," he half-laughed, a bitter and mostly-mad laugh.

And then he who had once been called the harbinger of death, the mighty Megatron, assured humanity's preservation in the only way he knew how.

Where do Sparks go when they go out? He had once asked an elder, when he was young and the responsibilities of Lord High Protector had not yet begun to grate on his sanity. The answer had been vague, as all answers were for younglings that age, but yet Megatron knew they had to go somewhere. He had then discussed the matter with a precocious young scholar who had then been called Orion Pax. In a way that hinted at the somber tone he would later take as Prime, Orion- Optimus- had simply told him that energy could neither be created nor destroyed, and that had satisfied them both.

Megatron laughed again, a broken noise that resounded like some sadistic mockery of a dirge among the burning buildings and the ruin of Chicago. The blaster tipped up, up until its round muzzle touched the angular rim of Megatron's face and he could see the energy building down its barrel. "I... am... Megatron," he boomed, punctuating the statement with a spray of acid rust.

Such was the day the war ended... for all of us.