[She doesn't know how much Terra knows already, so Korra decides starting with a brief introduction is probably for the best. She checks around the room just one last time before she begins talking.]

Did you ever meet Maris and Caeli? They're the ones who sent out that message when the whole place was flooding. Anyway, they were looking for someone--the Bridge. That's who we found when we kept going, all chained up and everything.