"Doctor Tenenbaum, of course!" He says, snapping his fingers. "I ought to know you anywhere, my apologies." He keeps his tone warm, sincere. It's the truth, though. This is the woman who made almost all of this plasmid business possible. Without her work in the labs, Sinclair's not sure what he'd be doing right about now.

"I would introduce myself, but it sounds like that won't be necessary. What brings you all the way out to this lovely corner of Rapture?"

Maybe Jack isn't in a position to be amicable (is he ever?), but Sinclair can at least try his shot at friendly conversation.