With Booker permanently out of the picture, you take control of Elizabeth -- but there's a catch. No longer does she have the ability to open tears in the fabric of reality. So she's far more vulnerable, which results in an increased threat level from the legions of psychotic splicers roaming the crumbling aquatic paradise.
All hope is not lost, of course; being human, Elizabeth can make use of Vigors and Plasmids, and she's more than capable of wielding firearms and the trusty Skyhook -- erm, I mean Air Grabber. Honestly, Burial at Sea - Episode Two's greatest strength is in its deliberate approach to enemy encounters. The stealth in many of these sections evokes the speed and flow of Dishonored, though it's admittedly not as satisfying or empowering. A new Plasmid called Peeping Tom allows Elizabeth to turn invisible and see enemies through walls, which is particularly useful, given that there are precious few resources to scavenge. And her crossbow is a fine multi-use tool that allows her to put splicers down or distract that one Big Daddy lurking around.