When Carstairs and all his men defected to the terrorist side, they traveled to auxilary control to inform the terrorist commander via radio. They sent the sublevel guard to kidnap Dr. Rudyard Shelton and forced him to allow them entrance. They then contacted the terrorist commander, who arrived with his assistant Broughton and the team that kidnapped Lockdown.
However, at this time James' team arrived to rescue Shelton. The ensuing firefight quickly turned one-sided when the sublevel guard and the rogue experiments Slash and Agito switched to James' side. Pietrson was the only immediate survivor of the attack, having been shot in the kneecap at the entrance to auxiliary control, which put him out of the fight early. After a failed attempt to interrogate him, Atticus Ædelwulf took him out of sight and soon came back with the information James needed. Since James gave Atticus permission to kill Pietrson, he probably died soon after. (Darwin's Soldiers)