I am the Son of famed military scientist, Adam Fenix, I established a reputation as a brilliant soldier during the Pendulum Wars, earning field promotions and decorations.I was on a fast track to an outstanding military career, until the war with the Locust Horde began.
One long decade after Emergence Day, the Horde Army breached Jacinto Plateau's defenses and I defied my orders so I could save my own father. I was too late, and in addition to losing my father, I Marcus was charged with dereliction of duty and was sentenced to 40 years in Jacinto Maximum Security Penitentiary; while it's later shown that my father was mapping the underground tunnels of the Locust Horde (a detail integral to the plot of Gears of War), I was not aware of how important my father's research was when I attempted to save him, or if he specifically knew it related to the Locust. It can probably be assumed he did not, however, due to his death I'll never know.