Michael Griffin is the first American soldier of the 'Silent Knight' project; he has experimentally become an invisible man. In his personal military career before the procedure, he has served at the Middle-East battlefront, yet being condemned for some war crimes.
At the Reisner Institute, under contract with the Pentagon, during the preparations of invisibility Michael Griffin suffers an adverse reaction, and so he is thought dead since then. However, this isn't true: Michael Griffin has feigned his own death, for becoming a secret hitman for political targets. He deprives the medicines of a terminal patient, pushes another victim downstairs, and drowns another one aboard his fishing boat. Michael Griffin's jobs then get broader, particularly throughout the American north west.
Michael Griffin gets back to the Reisner Institute, for forcibly getting the shots of an anti-radiation medicine, the Buffer, without which he would die. However, at this point, he is being sought for all the crimes he has committed.
On his way for the medication, he then slays all the security personnel who got on his way, and then he held his military mentor, Col. Galvin Bishop (William MacDonald). In the confrontation, after being pierced by him with a pen, Griffin stabs him to death with the same item, in retaliation.
Still in need of the additional treatment, Michael Griffin lures Dr. Maggie Dalton (Laura Regan) to a train station. There, Griffin turns her into another invisible person, for leveraging synthesizing the cure, at a makeshift College laboratory. He then fears about being poisoned by the scientist, so he forces for a test on her first. After this is done, he decides to murder her, but another invisible-man prototype, Det. Frank Turner (Peter Facinelli), timely intercedes.
Michael Griffin defeats Turner in the ensuing fight, and then he returns to kill the female scientist once and for all. However, he then discovers that actually the two of them were sick, as she had deliberately poisoned the doses of both in the preparation, for stopping Griffin. In the end, Michael Griffin is stopped in his attempt for murdering the scientist, as Turner stabs him to death with a shovel.