You take the role of Commander Shepard starship Normandy, the last hope for all life in the Galaxy. Saren, a rogue member of the elite and untouchable Spectre agents, has discovered the secret to unleashing an apocalyptic force upon the galaxy, and only you stand in his way. To save the lives of billions, you must do whatever it takes to stop Saren and prevent the return of an ancient force bent on the destruction of all organic life.