[If Sans didn't currently feel so unsettled by this place, he might ask Sayori more about her mirror friend. As it is, and considering Sayori's shall we say delicate world situation, he decides they can save that for once they're back on the moon.

Turning away, he takes the lead and starts walking in a particularly deliberate way.]

Puzzles are a big thing back home. Here's a trick for a lot of mazes: you keep your hand on a wall and follow that, you'll get out eventually.

[There's a loud sound, like somebody banging on the mirror over and over. Sans hesitates for an instant before walking faster, not turning to look. If Sayori does, she'll see a desperate-looking Papyrus banging on the mirror from the other side, like he needs help.]