"Perhaps it's a kind of closure reaction. Maybe, all these years, no one has ever experienced it inside this swamp, so it must have formed a sealed vacuum inside."
"A sealed vacuum layer, which means that there are such things beneath us, right?"
"Exactly, that's the idea, but you might not have noticed, at the front position of this isolation layer."
As he spoke, he pointed in that direction.
"Hmm, I see it, what next?"
"Next is the fact that this place has shown signs of destroying the vacuum layer, and moreover, it could cause that enormous pulling force to suck things back in again. So, by the time they crossed this spot, they had already awakened them."
"I get it, that must be the reason. But now that I think about it, I really had some thoughts. If we were a little slower in our actions, could she have fallen through here completely?"