[Hiro fidgets uncomfortably. God, this is so weird. Callaghan's not his professor, he's not even his friend, and yet here they are. Hiro feels like he just bombed a test and is having to stay back after class for a serious conversation about his grades.

Or maybe his behavior. His grades were always top notch; not so much his attitude.]

...A little of both. I've never explored any farther than this, and there's - [A beat. Hrrrm.] - hazards?

[Don't kill him. It seemed like a good idea at the time. Options were slim.]

Gas pockets. Flooding. Or getting really lost, that'd be bad. Stuff that makes it a bad idea to go charging around down here without thinking about which way you're going, first.