An extended trailer for the upcoming single-player story mode part of Mass Effect 3 has just come out of the hallowed halls of BioWare. Coming out on August 28th, the latest installment will have Commander Shepard and friends exploring the depths of some underwater world in order to find a rogue Reaper ship with an attitude problem.

The expansion will have you traveling to new systems, gaining new weapons and even apparently role-playing as a Big Daddy from BioShock. Okay, maybe I’m jumping the gun on the last one, but the showcased scenes do include you piloting a giant mech underwater just the same. This will be the first DLC for the single-player mode since launch which included day-one DLC of a Prothean.