With the failure of its past invisibility experiments, the US government brings in molecular biologist Dr. Maggie Dalton (Laura Regan) to work on a new serum. Volunteering to test the formula is Michael Griffin (Christian Slater), a soldier/assassin. Turning invisible, Griffin discovers a painful side effect: the serum causes his body to decay. Searching for a cure known as "the buffer," Griffin proceeds to hunt down and murder the scientists who worked on the project. Assigned to protect Dalton is Frank Turner (Peter Facinelli), a police detective whose partner is killed by Griffin. Injecting himself with the invisibility serum, Turner realizes he must fight fire with fire if he's to thwart Griffin and save the doctor.