Earth is burning. Not everyone will survive. An ancient alien race, known only as "Reapers", has launched an all-out invasion leaving nothing but a trail of destruction in their wake. As Commander Shepard, an Alliance Marine, your only hope for saving mankind is to rally the civilizations of the galaxy and launch one final mission to take back the Earth. You determine how events will play out, which planets to explore, and whom to form alliances with as you rally a force to eliminate the Reaper threat once and for all.