Gregory Farrell is a member of the United States Military's Delta Force.
Gregory Farrell was identified in the U.S. / U.K. Motor Neuron Rapidity of Response tests as having extraodrinary reflexes, making him one of the few people who could disarm the CincLock-VII security system.
Farrell and another Delta member, Dean McCabe, were tasked to lead their teams to Siberia on a mission to liquidate some hostile forces inside a former Soviet missile silo known as Krask-8, with Shane Schofield intended to arrive as backup. While in Siberia, Farrell and McCabe's teams were ambushed by Executive Solutions, and both leaders were decapitated to claim the price on their heads as part of a group of billionaires called Majestic-12s plan. Schofield later finds the bodies when his team arrives in Siberia.
Schofield later took revenge for Farrell and McCabe on Cedric Wexley by crushing his head under a door.