LOS ANGELES (AP) - "BioShock" is returning to the sea.

LOS ANGELES (AP) "BioShock" is returning to the sea.

Irrational Games creative director Ken Levine says that an upcoming downloadable chapter for "BioShock Infinite" will be set in Rapture. The fantastical underwater metropolis served as the locale for the original "BioShock" shoot-'em-up video game in 2007. The follow-up "BioShock Infinite" was set in the floating city of Columbia and released earlier this year. "Infinite" was the top selling game in March, according to NPD Group.

Levine said Monday a two-part story-driven chapter will feature "Infinite" protagonists Booker DeWitt and Elizabeth in Rapture, while the first edition of downloadable content is a fighting-focused mode called "Clash in the Clouds" that takes place in four unseen areas of Columbia. The first chapter is set for release this week for PC, Xbox 360 and PlayStation 3.