Fill of a prompt on the Tron kinkmeme:
AU of Legacy's end. Clu is winning. Quorra and Kevin Flynn are gone, derezzed by Rinzler. Tron is beyond saving, and Sam is the only one who makes it out of the portal in the end. But in his grief as he goes over the program code from the outside, he discovers a glitch in the Grid's timekeeping codex, which is causing the entire system to loop. Sam returns to the Grid and finds that everything returned to the way it was before he stepped out of the duplicate Arcade the first time. This time, he knows what the score is - he has his Grid-clothes, his Identity Disk, his dad's location in the Outlands, and - thanks to a quick stop to Alan's place - the knowledge of how to restore Tron from Clu's corruption. Of course, nothing is ever as easy as one might think.
The Iso gave the shell-shocked User a shove towards the portal, sparing only a nanosecond to witness his stumble before she was turning back to face Clu. Her lightdisk came up just in time to prevent the searing white edge from taking her scalp off. The high-pitched whirr as the two chakrams clashed sounded in Sam's ears like his old CD drive had, when he'd gotten the bright idea to amp up the speed and test whether a CD could withstand that sort of g-force without snapping. It hadn't; he had the scar on his left arm to prove that.
Funny, what the brain comes up with when your world's been torn from under your feet.
He stumbled again, then ran; legs pounding, heart racing, the corners of his eyes prickling with heat. Towards the portal, across the chasm, skidding on the slippery surface as he reached the outer maelstrom of light and raw digital material; heard behind him a cry of rage and pain and denial, before it was brutally cut short. He twisted around and met Clu's gaze across the distance. And as the program broke into a desperate sprint towards him, Sam stepped backwards into the light.
Lifted the disk in his hands, not his but his father's. Raised it up, above his head, felt it slip free from his fingertips. Closed his eyes against the brilliance and blinding-
Sam's legs collapsed under him, tingling with the after-effects of the transfer, and he let himself sink to the cold concrete floor, burying his head in his hands. The rage and helplessness pent up in his chest released into harsh, staccato sobs that echoed off the basement's walls, drowning out the dull thud of 80's-era techno from the arcade upstairs. He'd found his dad and lost him again in a single night. Dad had only winked and handed Sam his Identity Disk with a smile that didn't reach his eyes, before racing off to procure them each a one-man lightjet.
Sam pressed the heels of his palms into his eyes until he saw stars, bursting with light against the backs of his eyelids like the shine of Grid circuits. If they'd only stayed together – but Rinzler had focused on Kevin, for some reason, while the rest of Clu and his Black Guard chased after Sam and Quorra, and pursued him doggedly in an aerial battle over the Sea of Simulation. And then, though the memory was hazy, Sam remembered seeing...change. A flicker of blue bleeding away the red of Rinzler's circuits, and Sam remembered Dad's stories, hearing him mutter with such sadness on the Solar Sailor platform, a name…and then Tron had pulled sharply up, arced, spun out as his circuits flickered blue-red-blue-red-blue-red, base code warring with rectified programming, slamming into Kevin's lightjet, sending them both spiraling down and down and down into oblivion.
A soft bleep from the softly humming console drew Sam from his grief and he wiped at his eyes, pulling himself together and off the floor. He sat down at the console, not daring to touch it and risk the laser reactivating. The screen had gone blue, white letters glaring an error message through the layers of dust.
Operating System Error
Restore From Backup? y/n
Sam felt something cold and tight coil in his stomach as he stared at the words. Hesitant, shaking fingers rested on the touchscreen keyboard.
-Request information: backup timestamp
Timestamp: Backup Created 17.12.2010 10:23pm
He sat back, stunned. If the computer created a backup of the system every time the laser was activated, then…
Then Dad and Quorra…
"I need to get Alan."
Restore From Backup? y/n
System Rebooting From Last Restore Point
A/N: And then the Grid is completely restored to the exact point it was when the laser activated and pulled Sam in, only he's run off to get Alan and possibly Roy into the loop, and they rez in and save Tron and kick Clu's ass and rescue Kevin and Quorra.
At least, that's what would happen if someone else had filled this prompt, instead of me having to fill it myself when I posted it in the first place. However, since this was all that my brain gave me as inspiration, this is all I can post.