Colonel Frank Simmons, a shadowy figure from the Pentagon, had been recruited by Maybourne. Also known as User 4574, he carried out the secret agenda of the NID, although his direct chain of command was unclear. He was involved in the oversight of the SGC, including surveillance and interrogation of SG-1 following the contact with Orlin from Velona and Lieutenant Tyler of the Reol. He also shot O'Neill in the back and took custody of the escaped Goa'uld within Adrian Conrad, holding him at a secret NID location.
Simmons was eventually arrested when incriminating evidence was uncovered by O'Neill and Maybourne after he attempted to blackmail Hammond for a Goa'uld ribbon device in exchange for information to rescue Teal'c from within the stargate matrix. However, when rogue NID operatives hijacked the Prometheus, they demanded the release of both Simmons and Adrian Conrad in an attempt to locate a secret cache of Ancient weapons. In a struggle between Simmons and Conrad on board the Prometheus, Simmons shot Conrad and was taken as a host by Conrad's symbiote. As a Goa'uld, Simmons struggled with O'Neill and Teal'c, and he was sucked out of the airlock door of the Prometheus and left to die in space.
Portrayed by: John de Lancie