As anticipated, Irrational Games and 2K revealed their upcoming content expansion plans for BioShock Infinite today, unveiling Clash in the Clouds --an arena style challenge mode, available today-- and the more substantial Burial at Sea, which is due in Spring (Northen Fall), and will feature an all new narrative that takes players back to the undersea city of Rapture for a new adventure (thanks theborg).

This first add-on pack puts an intense focus on BioShock Infinite combat. Combine weapons, Vigors, Gear, Tears, and Sky-Lines in ways you never thought possible as you square off against impossible odds. This pack features 60 challenges in four brand-new environments. Complete Blue Ribbon Challenges and unlock concept art, Voxophones, Kinetoscopes, and more in The Columbian Archeological Society. Climb the Leaderboards and earn new Achievements and Trophies.

Burial at Sea features Rapture as you’ve never seen it before—a shining jewel at the bottom of the ocean, built almost entirely from scratch in the BioShock Infinite engine. Gameplay has been modified to give the player an original BioShock combat experience that merges the best parts of BioShock and BioShock Infinite: new weapons, new Plasmids/Vigors, Tears, Sky-Lines, and Big Daddies.

Explore the city when it was at the height of its beauty, meet some old “friends,” and make some new ones, all through the eyes of Booker DeWitt. Why are Booker and Elizabeth in Rapture? What was the city like before everything fell to pieces? The answers to these questions and more will be found in BioShock Infinite: Burial at Sea – Episode 1.

Clash in the Clouds is available from today for US$6.99/400 MS Points, and Burial at Sea is due to drop in the Spring (US Fall).