The team, now designated SG-1 (initially there will be nine exploration teams in all, more will be added later) are planning their next foray through the gate as they try to map out the variety of sites available to them and locate their missing friends. O'Neill asks that Teal'c be allowed to join his team but Gen. Hammond thinks that will be unlikely given that he is the host for a Goa'uld. Unknown to anyone, however, is that O'Neill's close friend, Maj. Charles Kawalsky, leader of SG-2, has been infected by a Goa'uld, an immature version that has not yet taken ...
The SG-1 team is sent after the SG-9 team that has failed to return. They find that SG-9's captain, having been treated like a god by planetary inhabitants, is drunk with power and is tyrannizing them. Can they overcome him?
When Jack is injured unintentionally by a crystal alien, the alien duplicates Jack's form and out of fear of retribution tries to heal Jack. He returns to Earth in place of Jack, while Jack is still unconscious on the planet, to find the one thing he feels will accomplish this; the one thing that cannot be found again. Meanwhile, the 'real' Jack has returned and is trying to convince SGC that he is who he says he is.
With the Stargate program in danger of being terminated, the team is under pressure to find technology. Visiting a planet where they believe there is a creature that possesses the secret of invisibility, they encounter Apophis and his guards. Both sides receiving mortal wounds, they are aided by the planet's inhabitants, the Nox, a gentle people with a very large secret.
SG-1 goes to the planet Cimmeria in search of allies against the Goa'uld. Upon arrival, Jack and Teal'c are trapped in a labyrinth, where the only exit is through Thor's Hammer, a device to destroy Goa'uld, but preserve the host. Daniel Jackson must destroy the device that could someday have saved his wife in order to free his friends.
Daniel Jackson discovers that the Stargate was activated in 1945 and a young professor went through, never to return. Together with his still living fiancée, the SG1 team discover the now aged professor, naked and trapped in a decaying fortress, containing the secrets of an Ancient alliance. Will they be able to rescue him and escape to earth in time?
O'Neill, Carter and Teal'c return through the Stargate shell-shocked and distressed to announce that Daniel Jackson was killed. But Jackson was captured by the last survivor of an aquatic race, who planted false memories in the other members of SG1. Can the team remember and return to rescue Daniel?
The Goa'uld Hathor (one of the mothers of all Goa'uld), brainwashes the men of the SGC with pheromones, and nearly makes Jack a host to a larva conceived with Daniel. She flees after the unaffected women of Stargate Command retake the facility.
SG-1 rescues a small girl who turns out to have had an inoperable Naquadah bomb put in her by Nirrti to destroy the SGC. Ultimately the girl is given to the care of Janet Fraiser, the SGC medic, after they discover that the bomb will dissolve if she is kept away from the Stargate.
SG1 travel to a planet where Teal'c is recognised as once having been head Jaffa to Apophis. He is arrested for the murder of a villager and put on trial for his life. Then other Jaffa attack the village. Will SG1 be able to save Teal'c and prove that he has changed allegiance?
On their first visit to a new planet, SG-1 finds it subject to totally destructive volcanic activity and saves ten natives, the Tollan, a far more technologically advanced society. Their leader Omoc isn't grateful, nor interested in such a primitive race as the earthlings or any of the 'even more primitive' planets which are prepared to host them. Only one Tollan, Narim, shows an active interest in life on earth, especially in captain Samantha Carter and the cat Schrodinger she gives him, explaining his planet was destroyed after the Tolan supplied an unlimited energy...
Following a Stargate technical defect, O'Neill and Carter are stranded next to a Stargate in a cave on an icy wasteland. O'Neill is severely wounded and both are freezing. Will the SGC find and rescue them in time?
Upon arrival on planet PX3,989 the team are rendered unconscious. When they wake, they return to Earth, but soon find out that they are Androids. The team must return to the planet to find out what happened to their real bodies.
While collecting artifacts on a distant planet, Daniel Jackson is knocked out after touching a mirror-like object. He awakens in the same room but is unable to locate the other members of SG-1. Assuming that they left without him, he dials up his return home but gets there to find that he is in a different reality. In this world, General Jack O'Neill and Catherine Langford are in charge of the Stargate program; Hammond is a Colonel reporting to O'Neill; and Sam Carter is a civilian scientist working on the project (and also engaged to O'Neill). More importantly, Earth...
General Hammond has tried everything to get the senates decision to shut down his space program undone, but the president personally refuses to 'commit political suicide': the Stargate will be buried. Daniel's insistence the danger for earth as a whole outweighs everything convinces his military SG-1 colleagues to ignore the commander general's command and dial the address the goa'ald invasion started from in the parallel dimension he visited. They arrive not on a planet but a new, superior type of starship, already launched by hyper-drive. A 'video' proves it belongs...