After S.T.A.R.C.O.M. disbanded, Flash Sentry prepares to leave Stallion City and take down Parasol. Unfortunately, the city is in total chaos. A plague had silently turned the unsuspecting citizens into zombies. To make matters worse, a biological weapon is hunting down S.T.A.R.C.O.M. members to prevent them from revealing Parasol's secret bio-weaponry. Once again, Flash, Twilight and her brother Shining Armor must rely on cunning and brute force to escape.