Nightwalkers

Nightwalkers is the fifth episode of the sixth season of Stargate SG-1.

Plot
On a rainy night, a man named Dr. Richard Flemming calls Major Carter while driving a car. He tells her that he knows about Adrian Conrad and what happened to her but suddenly there are crashing noises and the connection is terminated. At Stargate Command Carter informs the others about what she found out. They also found out that while Flemming's car was badly damaged Flemming himself is missing so they decide to investigate. However, O'Neill can't come with them since the Tok'ra still need a host for his symbiote who cured him from the disease (see "Frozen").

Carter, Teal'c and Jonas are ordered by General George Hammond to drive to the city where Flemming worked and there Carter questions the sheriff. He tells her what he found out about him and it turns out that his laboratory was burned out. So the trio decide to check his house but they find absolutely nothing. Suddenly someone brings a package and it turns out that it comes from Flemming himself and that includes a syringe. They decide to investigate further about Immunitech, where Flemming worked. At night many people gather in a house elsewhere in town and decide to do something if the "uninvited" three from SGC find anything of significance.

The next morning Carter tells them that she didn't find out anything but Jonas says that the people in the restaurant where they eat act strangely. Suddenly a policeman comes in and brings Carter to the sheriff who tells her that someone laid the fire at Immunitech. He also tells her that two months ago another worker at Immunitech named Peter Stofer vanished and was never found. He then shows her documents which reveal that Stofer worked with Flemming. In their motel Carter tells her friends that Stofer and Flemming ordered material on stem-cell research which could be used for cloning.

In the evening Jonas and Teal'c enter a restaurant but they nearly get in a fight with three men until the sheriff intervenes. After Jonas and Teal'c leave, the sheriff tells the three that they shouldn't "disturb the operation." The next morning Jonas sees one of the three men again in a restaurant but he doesn't remember him. When they leave it they see a man watching them and capture him. He tells them that he was a security guard at Immunitech who believes that Flemming was murdered. The three then think about what could go on in the city and suddenly Jonas remembers something at the shipyards. They look at it and find a lot of hardware and in another room a spaceship.

While Carter tries to decode some discs they took from the shipyards, Teal'c and Jonas investigate the yards. Suddenly several people appear there while Carter finds out that the information on the discs is written in Goa'uld language. She informs her friends who are suddenly captured by several men while many other people arrive at her motel. In their van a man named Agent Cross tells Teal'c and Jonas that they belong to the NID and watch these people since they are all infected with cloned Goa'uld. They especially want the spaceship.

Meanwhile Carter is stunned by the sheriff and infected with a Goa'uld. When her friends arrive at the motel they find her missing and tell Agent Cross to do something. However one of the agents stuns them with a Zat. They are brought to where Sam is and Cross is infected with a Goa'uld. They then want him to infect the rest of the NID. When he leaves the Goa'uld in Carter says that they should kill Teal'c and Jonas. Meanwhile a containment team arrives and reports to Agent Cross, who wants to go to the headquarters. Suddenly Carter appears and after talking with Agent Cross she stuns them with the Zat.

Back at SGC Carter reveals that the substance in the syringe prevented the Goa'uld from taking her over. Hammond then tells them that all other citizens are freed from the Goa'uld and that the spaceship is brought to Area 51 for further studies.