Watch the BioShock Infinite: Burial at Sea Launch Trailer

BioShock Infinite is getting a major expansion with the release of Burial at Sea, a standalone-ish storyline split into two chapters, the first of which is out today. To celebrate its release, 2K Games has published the launch trailer.

The game takes place prior to the events of the original BioShock and places the characters we've come to know and love from BioShock Infinite within the setting.

Here's what's up: "On the eve of Rapture's fall from grace, Elizabeth enlists Booker DeWitt's services in locating a lost girl. Who is this girl Sally, what does Booker know of her supposed fate, and what is Elizabeth's connection to this mysterious child? Find the answers to these questions and more in this new addition to BioShock Infinite, built nearly from scratch by Irrational Games."

Watch the trailer below.