Okay, so maybe he's going to have to be a little more specific with his questions if he wants any answers. But there's no harm in a little give and take, so Sinclair answers.

"Well I'm not sure what they were supposed to be originally, but for Fontaine it's laboratory of sorts, I suppose. Research facility, you could call it. It's where those plasmids you've been using were developed, still are. Trying to get them a little more stable, minimize the consequences of using them. Among other things."

He stares out of the bathysphere porthole, watching a school of fish disperse as they pass. He never did get used to the scenery down here, it seems to be the one consistently good thing about Rapture. In taller buildings, when you're a little closer to the surface, the sunset turns the whole city a burnt orange and red, fading into purple like a watercolor painting. Breathtaking, really. He'd never seen anything like it before. Sometimes you can stand at a window and look out at the ocean for a while and just forget. Everything is so peaceful out there, and then you come back to yourself in here. This place isn't a dream for anyone, even the now most successful businessman in Rapture. The money's there, but sometimes he has to sit down and figure out his priorities.

Which brings him back to Jack.

"How'd you end up here anyway?"