If it's not too late, Jack's in! lmk if it's cool for Jack to overhear something and then check it out himself. He'll keep his distance but you're damn right he's going to explore those tunnels, man.

EDIT: I forgot to mention he's one hell of a scrapper--if someone's there by accident and they need someone to get them out of the way of tunnel monsters or anything, give me a shout! Similarly, if anyone wants to potentially save Jack's ass, too, that's always cool. :3