"Probably pretty stable. I mean, they're still up, aren't they?" That doesn't sound right. He vaguely remembers all those safety videos they had to watch in third grade explaining that mines are always dangerous, but he was always more distracted by the video clip of the kid with the motorcycle falling down the well-shaft.

"There's a tunnel in here too from the meteorite, probably. You'll tell me if the air's going bad in here, right?"

Howard doesn't necessarily want to explore the mine, but Zouichi seems interested, and he trusts Zou to keep him safe. Even from Space Jesus or whatever the hell was down here back home.