"It's... not the worst thing," Papyrus tells his brother, since... Yeah. Talking people out of things hasn't had the best track record.

"This doesn't need to be a surprise. It's better if it's not! If she knows we're here, and lashes out... We'll know that she's not friendly, yet."

Which, might spell a speedier and more certain doom than the magical fog, if she's particularly aggressive about it. He focuses on his blue magic, readying himself to ping souls and tug people - including himself - around to safety, if need be.

"And, if that happens, we'll lure her outside, so we're not in a tunnel of foggy death with her."

With a decisive nod on his foolproof plan, Papyrus rushes after the others.