SG-1 faces two potential disasters light years apart as an energy build-up in the Stargate threatens to destroy Earth and another world. Teal'c returns home to find out that his wife is dead, his son is estranged, and his planet is under attack.
Teal'c and his son, Rya'c, battle to save Earth. Meanwhile on Earth Jack pilots the x-3, a newly designed interstellar spacecraft that will carry the Stargate far away from Earth so it can explode harmlessly in deep space. This could be the end of SG-1 as there will be no more Stargate.
Carter and Jacob in a Goa'uld cargo ship discover a derelict Goa'uld ship orbiting Earth. SG-1 tries to salvage the ship, but sabotage causes the ship to plummet to Earth, crashing into the Pacific Ocean. The team must figure a way to save themselves, and possibly the technology on the Goa'uld ship.
The team discovers a frozen Ancient, who once revived, exhibits magical powers.
When Sam receives a late night call from a scientist who speaks Adrian Conrad?s name, and then he subsequently disappears, after his car crashes, leads the SG-1 team to investigate the occurrence. It is learned the scientist is connected with Adrian?s past company, which was working on curing his failing health via a Goa?uld implant. The team, upon going to the small town Adrian?s research lab was relocated to, find the townspeople?s behavior during the night very bizarre. It?s assumed the Goa?uld are present, but the team must discover what their ultimate plans are. The team also learns that the N.I.D. is also involved in some way, too. The team must determine their intentions too.
A Goa'uld lord, named Baal, holds Jack captive and tortures him for information about the Tok'ra. As Jack suffers Daniel appears and offers support. Meawhile the rest of SG-1 races to rescue Jack before it's too late.
Jonas is conflicted when an old professor from his home planet asks SG-1 to help stage a coup against the Kelownan government in order to stop a civil war.
Three bumbling Scientists working on an off-world research project witness SG-1 being captured in a Goa'uld raid, and defying orders, two of them attempt to rescue the the SG-1 team. What they don't know is the SG-1 staged the capture in order to infiltrate the Goa'uld, in order to make contact with a Tok'ra informant. Can SG-1 complete their mission and also rescue the bubbling scientists?
Fleeing a Goa'uld attack, the Tok'ra must take refuge at the SGC Alpha Site occupied by rebel jaffa. Centuries of bad blood between the two races begins to boil as an unseen assassin wreaks havoc on the camp.
SG-1 visits Pangar, a planet inhabited by humans who have developed a drug that makes their immune systems perfect. The way taht the drug is produced may hold the key to the origins of the Tok'ra.
Rogue NID officers hijack the top secret x-303 spaceship with Sam and Jonas on board and demand that Adrian Conrad be brought to the ship. Using his Goa'uld knowledge Conrad activates the X-303 and takes the ship light-years away from Earth as Jack and Teal'c stage a daring rescue, not knowing if they will be able to return home.
When SG-1 is marooned in deep space, Thor and the Asgards come to the rescue. They then seek Jack's help to combat the Replicators, who have overrun their home world. Convinced they will attack Earth if not stopped, Jack stages a daring mission to stop the Replicators once and for all.
SG-1 returns from a mission with an ancient artifact that triggers the ability to see hideous, yet harmless life forms, in a parallel reality. As the effects spread to civilians SG-1 must find a solution before mass hysteria breaks out.
Senator Kinsey suffers an sleepytime attempt while campaigning for the presidency and Jack is caught on tape leaving the building where the shots were fired. With Jack behind bars, Sam, Teal'c and Jonas must prove his innocence before it's too late.
Jack and the man who he loves to hate, Harry Maybourne, are both transported to a now dead former utopian society. There a drug makes Harry paranoid and he tries tohug Jack, will help arrive in time?
When the Russian SG team returns from a mission to a planet early, and with an unannounced dying alien, against protocol, the SG-1 finds signs that Niirti is again up to no good. Upon investigation, they discover Niirti is performing experiments on the planet's population; terrible, mutating, disfiguring experiments. Unfortunately, the people there believe Niirti is trying to cure a disease they have, and capture the team. Now they have to escape from the people they are trying to help, and avoid being the next guinea pigs in Niirti horrible experiments!
When the U.S. and Russia decide to disclose the existence of the Stargate program and their contact with people and aliens from other worlds, the Ambassadors attending this conference are stunned, shocked and appalled they were kept in the dark. Things are then made worse when Senator Kinsey uses the conference as an opportunity to try to discredit the SG-1's work, and the SGC in general. Kinsey wants the attendees to demand that Stargate control be move to the N.I.D. He gives the group examples on how the SG-1 and SGC have nearly brought destruction to the Earth on many occasions, and has showed a great disregard for Earth's safety. Hammond, SG-1, and those from the Pentagon, must try to dissuade the attendees from listening to Kinsey's opinions. They must try to counter his negative criticisms with positive points made about the team's, and the SGC's successes, and their defense of Earth on many occasions. Can the SGC survive Senator Kinsely's onslaught and keep control, or will the secretive N.I.D. take over Stargate Command's operation?
SG-1 discovers a crashed alien ship on a distant planet. The first group that they discover, human survivors, claims that the prisoners they were transporting have escaped after the crash. The team tries to help them recapture the prisoners, only to find not everything is what it seems. Who can the SG-1 team really believe? Determining the answer to this question puts the team in serious risk.
Teal'c is confused as to what is reality and what is not when he goes between two realities. The first, he is a man with a wife and is donating a kidney to his step-father. The second, he is a firefighter. In the first reality he is presented with a dilemma from Daniel Jackson; what if neither one is real?
The SG-1 team is required to accompany the maiden voyage of Earth's first trans-galactic space ship, the Prometheus, even though the really don't want to. Things go wrong, and the ship becomes disabled, and the ships corrective actions lead to devastating effects on a nearby planet. SG-1 works to persuade the planets inhabitants that the devastation was just an accident. The planet turns out to have the one thing the ship needs to get home safely.
On a routine misson, SG-1 encounters a civilisation desperate to be freed from the clutches of the Goa'uld. While on the planet, Jonas falls ill and starts having visions of the future, he is diagnosed with a brain tumour and has a vision where SG-1 are walking into a trap on the alien planet.
Daniel Jackson appears to Jack and alerts him that the Goa'uld Anubis is going to launch an attack on the planet Abydos and destroy it unless he gets the eye of Ra that he believes is there.