In the Line of Duty

In the Line of Duty is the second episode of the second season of Stargate SG-1.

Plot
As SG-1 helps a group of people on the planet Nassya flee through the Stargate from a Goa'uld attack on their world, Captain Carter stops to give CPR to a fallen villager. He suddenly grabs her head, and something enters her. Blood on her lip, Carter's eyes glow. She has been possessed by a Goa'uld symbiote.

Carter returns through the gate and tries to act as normal as possible, though through the mission debriefing her comrades notice something is different about her. Dr. Fraiser invites her to come check on the Nassyans, many of whom have been moved to the hospital at the nearby Air Force Academy. Finally, she goes to visit Cassandra ("Singularity"), and the young girl senses that Carter has been taken by a Goa'uld. She locks herself into Dr. Fraiser's office and demands to see Colonel O'Neill.

Meanwhile, one of the badly burned refugees assaults his doctor, and emerges from his bandages fully recovered. He is an Ashrak, a Goa'uld hired assassin.

Cassandra convinces O'Neill that Carter was infected, and he takes action. When he injects Carter with a serum that "would bring down an elephant", the Goa'uld inside her becomes active and demands the Stargate be activated. Carter is apprehended and put behind bars at the SGC. The Goa'uld reveals itself to be Jolinar of Malkshur, and demands release. The parasite even promises to return Carter to them, fully restored to who she was. O'Neill does not budge. Suddenly, Carter's personality emerges and begs O'Neill to believe Jolinar but he takes it as a Goa'uld trick.



Finally, Jolinar reveals that she is a member of the Tok'ra, a group of rebel Goa'uld who oppose the System Lords and seek power for good. They are the most hated enemies of the System Lords, who constantly chase down any leads in an attempt to infiltrate and destroy them. She also explains that the System Lords will not allow the Tau'ri to thrive and become a threat. Already a far more powerful attack is being planned. Teal'c, at least, is convinced. Jolinar talks with Daniel and tells him she knows where Sha're is.

When the Ashrak finally locates his victim, Jolinar, Carter suffers torture and almost death at his hands. The hunter is found, and Teal'c finally kills him with two shots from a zat gun, also stunning Daniel in the process. Meanwhile, Carter is fighting for her life in the infirmary. When she recovers, she tells O'Neill that Jolinar has given its life to save hers.