The original story is The Reason Why by elizajeanb1.
Neither of us own The Stanley Parable.
The building was similar to that of the 'Stanley Parable', only there were major differences. Instead of the normal white walls and orange carpeting that he usually saw, his gaze was met with brownish-grey walls and a concrete floor. The doors were metal instead of the normal white plastic and there were no windows that he could use to peer into the rooms or outside.
The female voice from before chuckled. "I see you've noticed the differences between your office and mine."
The Narrator walked around the office area, trying to see if there was anything that could give him any clues. He turned on the computers, but nothing useful showed up on them. It was the same thing when he looked through the papers on the desks.
"Nothing there will help you with the maze," the female voice said, trying to urge him to keep going. "You just have to follow your instincts and choose a path."
The Narrator looked up at the ceiling and walked along the hallway. 'This is probably how Stanley felt when he first started as the main character in our game,' he thought. 'I hope Stanley's alright.'
The Narrator felt a sharp pain in his chest at the thought of Stanley in any sort of pain. He deeply cared about and loved the office worker, though he never admitted it to anyone but himself. Whenever Stanley was happy, the Narrator felt happy. When Stanley was sad, the Narrator felt sad. They had connected on a deep level. If anything bad happened to Stanley, the Narrator wouldn't know what to do.
The Narrator soon reached a set of two doors similar to the ones Stanley would encounter in the 'Stanley Parable', only they were the metal ones the Narrator had encountered up until this point. He had to choose. Left or right.
He walked up to the left door and peered inside without walking through it. He couldn't see anything, but he knew there might be traps here. He did the same with the right door, only he looked for any differences between the two.
There it was inside the left doorway. A large, almost completely invisible pressure point was just beyond the door. It was so long and wide there was a slim chance he'd be able to jump over it, and there would be no guarantee that there are no more traps beyond here. Yet he felt this urge to go through this door, some instinct that told him Stanley was beyond this point somewhere. There wouldn't be any traps if Stanley wasn't in this direction, right?
The Narrator backed up as far as the room allowed and rushed forward, using the walls to help propel himself forward and past the pressure point. He landed just on the other side of it and turned around as the door shut behind him.
'Looks like there's no way back,' the Narrator thought to himself as he continued forward.
The female voice suddenly showed up. "I see you chose the difficult path. I'm impressed, though. Your instincts led you through the correct doorway. Stanley is indeed this way, but you just gave up the only path that will lead you to freedom. You're really that determined to save Stanley, aren't you?"
The Narrator continued forward, trying to ignore the female voice.