The BioShock DLC takes place in arena-type levels designed to look like Rapture. The scenario we saw involved a little sister stuck atop a Ferris wheel -- she needs to be rescued! The first thing that has to be done: Hit the control box with the shotgun's electric buck, causing the wheel to move a little. To move it a little more requires finding a booby-trapped room featuring an electric crossbow inside a safe. Shoot the control box with the crossbow and cut the line to give it a charge, and the wheel moves a little more. Every electric item found will move the wheel a little more until the Little Sister is saved. No other scenarios were discussed.