A group of primitive aliens begin to fall deathly ill after SG-1 arrives.

A young boy arrives through the Stargate, and warns of plot by invisible aliens to kill all of the human race in order to rob the Goa'uld of potential hosts.

A cosmic accident causes SG-1 to be sent back 30 years into Earth's past, where they must locate the Stargate and find a way home.

When Major Carter's father Jacob is kidnapped by Sokar, the SG-1 team must infiltrate a prison moon designed to look like hell to rescue him.

SG-1 must escape a hellish prison moon, and one of their worst enemies.

An alien artifact causes Daniel to disappear, and the team looks for help from his institutionalized grandfather.

O'Neill and Teal'c are caught in a time loop in the SGC, and must relive the same 10 hours over and over again.

SG-1 must stop Apophis and Heru-ur from forming an alliance of their powerful forces, while Teal'c is captured and tortured by the Goa'uld.

SG-1 must rescue an alien world from the Goa'uld -- with help from an unexpected source. Teal'c seeks revenge on the System Lord Cronus for the murder of his father.