Something lurks in the dark corners of space, something powerful enough to kill a Reaper. Shepard must discover the most closely guarded secret in the galaxy before the Reapers silence it forever.
Mass Effect 3: Leviathan expands upon the events of Mass Effect 3, with gripping and emotional storytelling, compelling new characters, and powerful weapons and upgrades. Discover more about the origins of the Reapers as you race across the galaxy to find the Leviathan. Travel to new systems, wield the AT-12 Raider Shotgun and M-55 Argus Assault Rifle, and unravel the dark history of the Reaper Race before it is too late. On Aug. 28th there is no war, only the harvest.
Source: The Publisher Website.