On 10/18/20██ the following unauthorized modifications to the experimental data of SCP-2719 were logged by the external monitoring server. Based on the information gained from the logs, and the successful recovery of Site-81, Dr. Watkins has been given a posthumous commendation.

Pointer
Outcome

Site-81
Became inside.

SCP-184
Went inside.

Inside
Went inside.

Inside
Went inside.

Inside
Went inside.

Data Corruption
Went inside.

Population of Site-81
Went inside.

Meanwhile, inside…
Dr. Watkins ran. He didn't know whether he was running away from something, or towards something, but he ran. Other people ran on the ceiling beneath him. One of them was struck by a dozen glass books falling from a room on Dr. Watkins' right. No one stopped to help the fallen man. No one could reach him. He was There, and they were Here. Wherever Here was for them at the time. Managing to get from Here to There would have been quite the feat.
He ran for another hour. Ten seconds. Three years. He wasn't sure. Sometimes the doors whizzed past in a blur, and other times the halls stretched out for an eternity. A voice called out from somewhere else.
"Help me! I'm stuck!"
Dr. Watkins spun, trying to follow the voice. "Where are you?"
"Inside."
Some part of Dr. Watkins began to ask "inside what," but the thought was lost as he stepped through a door into a room full of origami locks. Of course the voice was inside. Where else would it be? "Don't worry, I'm coming," he shouted. He opened another door, into another, identical room. He turned to look at the room behind him, but saw instead a new hallway. There was someone moving at the end.
Dr. Watkins left the origami room and ran down the hall. The someone was above him, sitting cross-legged with its eyes closed. Dr. Watkins stopped and looked up at him. "Are you who was calling for help?"
The someone opened one eye and looked back. "No. I do not need help. Others would stop me from being inside." The eye closed again, and the someone was silent. Before Dr. Watkins could tell the someone that they were already inside, that they were still inside, a door opened, and the someone tumbled through it serenely. The door was too high up for Dr. Watkins to follow, so he settled for the one that had appeared in front of him while he spoke to the someone, and began running again.
The hall twisted in every direction as Dr. Watkins ran. Left, right, up, down, back upon itself. He checked every door he saw, looking for a light, a place that wasn't this building. Room full of steel furniture. Room like the site break room, but everything was upside-down. No room, just a block of warm putty behind the door. For a moment the doctor was sure that he was running inside a giant wheel, as each door led to the same empty interrogation chamber, tinted a pastel pink. But none of them had more doors. Each one was a dead end.
Dr. Watkins gasped as he opened another door, and nearly leapt through it into the open sky before him. He caught himself on the frame as he realized that the sky extended to the ground as well. Across the room was another door. It wasn't out, but at least it was progress. But how was he supposed to get across the sky? Dr. Watkins removed his watch and held it out, slowly letting it slip from his grasp. It fell onto the sky at his feet with a soft thump. He crouched and touched the area near the watch, and did not fall though either. It was warm to the touch. It was plastic, a giant computer screen with a background of skies. Dr. Watkins laughed, high-pitched and tense, and ran across the room, through the next door.
The running continued for a long time. Doors were opened, rooms were crossed, halls were walked, but no exit. No exit. There was no out. Was there an outside? Did an outside even exist? There may not be, but Dr. Watkins kept going.
The doctor's run had slowed to a trudge, breathing heavily. He was tired, he was thirsty, but he could not stop. The was nothing more important than getting out. He stepped on a platform made of notepads and slid across a room full of water, unblinking. Outside was the only goal. There was nothing more important than outside. If he could get outside, he could report this, maybe find a way save the others inside. He just had to find the outside. He stepped off the platform and into another hallway. Find outside, get out of inside, save the inside. Out of in, into outside, outside-in.
Dr. Watkins stopped dead in his tracks. Maybe that wasn't the answer. Maybe the someone was right. Maybe he needed to be inside. Maybe to be more outside, he had to be more inside. Maybe the outside was inside. Yes, that was it. He just needed to be more inside. More inside. He took a few steps, then stopped and turned, walking back the other direction. If he didn't know where outside was, how would he know where inside is? Where is inside? What is more inside?
More inside.
Inside.
In…
Inside?

Pointer
Outcome

Dr. Watkins
Became inside.

Inside
Went inside.

SCP-184
Outside.

Dr. Watkins
Inside-out.