Mass Effect 3 Leviathan Launch Trailer Ventures Beneath The Waves

Mass Effect 3's single-player add-on "Leviathan" won't be released until next week. However, that hasn't stopped BioWare from releasing a trailer with some enticing gameplay footage.

"Leviathan" is a new mission that takes place in the middle of the standard campaign. Commander Shepard hears reports of a being powerful enough to kill a Reaper. He and his team head to a remote mining facility to investigate.

At the facility, the squad encounters a Reaper army. While his companions fend off the Reapers, Shepard climbs into a diving mech and hops into the ocean below. The trailer closes as he encounters something huge.

What dark secret lurks beneath the waves? You'll have to pay $10 to get the DLC on August 28th to find out. Or you could just go here and spoil the surprise.