After a time, Sans calmed down enough to think clearly.

So...what now? Sans wondered. Would they reload? Was that possible here? He'd seen Frisk do that occasionally before, even when they hadn't died, after something happened they didn't like.

But nothing was happening so far. Maybe that meant he should try to do something.

He hit Rose's shield bubble half-heartedly with a few attacks to see if it was possible to break through.

Part of him hoped that it wasn't. He was sick and tired of bloodshed, and his growing doubts were making him more and more reluctant to fight. He felt a small twinge of relief when he found the shield was harder than diamond, harder than when Rose was awake. There was no way he was breaking through.

He turned to the computer instead. It was still open where it'd been left. From his science background, Sans was fairly familiar with computers. It confirmed what he had suspected for a long time. It really was a game. The timelines were controlled by a game. When he started it, Frisk began in the ruins.

He leaned back, massaging his skull with one hand, momentarily stunned by the revelation. Then he leaned forward again in the chair, taking control of the computer and investigating where the game was being run from. There was still another question to answer.

It seemed Rose had set up a network tunnel to another computer, and the current game on the screen was running there.

"Undertale..." he whispered. "So...if that's somebody else's game, where is her game? Is there another instance of the same program?"

Clicking out of the remote computer connection, he found her own game on the desktop. On opening it, he saw everyone was alive, together, and waiting for Frisk, right before leaving for the surface.

It was an odd moment, looking at a miniature version of himself. He really wished there was some way to talk to the other Sans, but that didn't seem possible under the game's mechanics.

"It's the good ending..." Sans murmured softly. "So, she was telling the truth after all...she was not the original player...but then why did she have so much LV? Could it be a trick?" The full truth still seemed out of reach.

There didn't seem to be any more answers to be found here.

There was apparently no way to return to his own timeline, either, by using the computer or anything else in the office. No time travel machine.

He tried opening the door to the hallway outside.