Four years after the war's end, a forgotten veteran known as Marcus lives in obscurity, scavenging metal for rations. A sudden Priority-One alert orders all combat personnel to report, shocking the community as a new Zerg invasion begins. The elite 'Silver Wing' mech force engages the enemy, but the battle turns dire. Amidst the chaos, the true scale of the threat is revealed, leaving Marcus and the survivors to face an overwhelming second wave and a tyrant loose in the city, forcing a desperate fight for survival.