Lt. Astor was captured by the Goa'uld on a mission and programmed as an assassin. Her programming was covered with false memories, but when an attempt to remove the programming was made, her self-destruct programming was triggered, causing her to commit suicide.
Lt. Astor was assigned to SG-14, Major Graham's SG team, along with Captain Blasdale and Sgt. Lewis. They were with SG-15 and at least one other SG team on P6Y-325, helping protect a village of Lasarians from an attack by Jaffa in gliders and on foot. The battle was intense and six SG team members were killed, but SG-14 made it back to the stargate and home safely. She thought they had beat the odds with their military savvy, but, unfortunately, that was not the case.
The Goa'uld were using a new kind of technology which implanted false memories into the victims. Not only that, but they also implanted a program to make the victim become an assassin. The Tok'ra Anise called these victims "zatarcs," named after the technology used to program them. The zatarc's programming would be triggered by a visual or auditory signal and there was no stopping him/her until the target was eliminated. If the zatarc felt that he/she could not accomplish the goal of the programming, he/she would commit suicide, usually resulting in the destruction of the zatarc's body so that the programming could not be detected in an autopsy.
When Major Graham and Captain Blasdale accompanied Colonel Jack O'Neill and Dr. Daniel Jackson in the Tok'ra underground conference room on Vorash to meet with High Chancellor Per'sus, Major Graham attempted to assassinate him. In the struggle to get to his target, Graham killed Blasdale and three Tok'ra guards. When he was about to be apprehended, Graham turned the Goa'uld weapon he was using on himself and blew himself to bits.
Anise had a new machine which she had developed to determine if someone was a zatarc. She created this zatarc detector after three Tok'ra operatives had acted in the same manner as Major Graham. She offered to interview all SGC personnel who had been on missions in the last two months to determine if any others had been captured and reprogrammed as Major Graham had. The first people she decided to interview were the remaining members of SG-14.
Lt. Astor retold the events of her mission to P6X-325. It was night and the Jaffa were all over the place. Captain Blasdale and Sgt.Lewis were cut off from their team. Astor thought that she had successfully killed the approaching Jaffa and made it to the stargate to return home safely. The zatarc detector indicated that that had not been the case.
Anise declared Lt.Astor a zatarc and offered her the choice as to whether or not she wanted to undergo the procedure to remove the programming. This procedure would involve damaging the area of the brain affected and the outcome could not be determined. Lt.Astor decided to undergo the procedure, because, according to Anise, if she did not, she would be self-destructive because she would not be able to achieve the goal of her programming.
While undergoing the deprogramming procedure, Astor felt a considerable amount of pain and begged Anise to stop. When Anise stopped, Astor's programming was triggered. She was able to free herself from her restraints and confiscate a handgun from one of the SFs stationed to guard her. She fired the weapon at the observation window and then she turned the gun on herself, fatally shooting herself in the head.
--DeeKayP 10:41, 27 Jun 2004 (PDT)