The player assumes the identity of JC Denton, a nanotechnologically-augmented ("nano-aug") UNATCO agent. After completing his training, JC takes several missions given by Director Joseph Manderley to trace down members of the National Secessionist Forces (NSF) and their stolen shipments of the "Ambrosia" vaccine, the cure for the "Gray Death" virus. Through these missions, JC is reunited with his brother, Paul, also a nano-aug. JC tracks the Ambrosia shipment to a private terminal at LaGuardia Airport. Paul meets JC outside the plane, and explains that he has defected from UNATCO and is now working with the NSF after learning that the Gray Death is a man-made virus, with UNATCO using its power to make sure only the elite receive the vaccine.