Irrational Games revealed the intentions for their remaining BioShock Infinite downloadable content plans to follow up the Clash in the Clouds DLC: Burial at Sea, a Booker and Elizabeth tale set on the eve of Rapture's downfall. Yes, you heard me. Booker and Elizabeth in Rapture! Together! ALL FILM NOIR-LIKE!
Burial at Sea will be released in two episodes. In the first, you play as Private Detective Booker who is enlisted by Elizabeth on some unknown task before Rapture falls. Players will be able to see Rapture in its prime including a built-from-scratch world and new characters, along with some old ones. The gameplay merges favorites from BioShock and BioShock Infinite, and includes new Vigors/Plasmids, tears, Sky-Lines, and Big Daddies.
But forget that boring stuff. In the second episode YOU GET TO PLAY AS ELIZABETH. Not much else has been said about this as they're just scratching the surface. From what it sounds like from my interview with Ken Levine (check back later today for that), the second episode will be more focused on survival horror and stealth mechanics.
Burial at Sea: Episode 1 (and presumably 2) will be included in the BioShock Infinite Season Pass, otherwise they'll cost $15 each. No release date has been set for either, but I imagine the first episode will hit before the end of the year.