|First Appearance||Size Matters|
|Portrayed by||David Marciano|
Gordon Greyson is a former scientist.
In "Size Matters" Gabriel and Riley goes to a warehouse to find Greyson when they find his manifesto written in numbers found inside a box which contained nanites that killed several scientists. When Greyson arrives he sees them inside and shoots them. He manages to escape through a trap door on the floor. He then get on a truck he had hidden earlier and escape. But Gabriel and Riley capture him when he was stopped at a red light.
When Gabriel and Riley interrogate him he tells them the government is the real terrorists. He says they are planing on implanting chips on our brains and Frankenstein's monster will soon walk among us. Gabriel turns off the cameras and tell Greyson information about him to scare him off. Riley receives a phone call. He then starts to bleed from his nose and dies.