Tragedy reunites Teal'c with his son, who blames him for the death of his mother. O'Neill and Carter launch a risky plan with untested technology when Earth comes under attack by the Goa'uld.

Carter must find a way to save Earth from total destruction at the hands of the Goa'uld, who have turned the Stargate into a doomsday bomb. Rya'c joins his father on a mission to destroy the Goa'uld weapon.

SG-1 boards an abandoned Goa'uld mothership that has mysteriously arrived in Earth's orbit, and must escape the doomed vessel when it crashes into the ocean.

SG-1 investigates the discovery of a woman frozen in the ice in Antarctica, who may be a link to the gate builders. A mysterious disease threatens to kill everyone at the research base.

Carter, Teal'c and Jonas investigate the death of a scientist with connections to the Goa'uld, and find a small town whose citizens harbor a dark secret.

O'Neill is captured and tortured by the Goa'uld System Lord Baal, and must rely on an old friend to survive.

Jonas' people ask Earth for military aide in an impending war with their rival nations, but his former mentor offers another solution: a resistance movement ready for a coup.

When SG-1 is captured by the Goa'uld, a pair of scientists mount a rescue operation whether they're wanted or not.

Tensions rise between the Tok'ra and rebel Jaffa at the S.G.C.'s offworld base when they are attacked by an invisible enemy.

An alien world offers Earth a medicine with the power to cure any illness but the hidden price may be too high to pay.

A news reporter threatens to expose a top-secret military project, but when Carter and Jonas give her a tour of the X-303, they discover that she is a pawn in a much larger plot.

The team is called into battle unexpectedly when the Asgard homeworld is overrun by Replicators which have evolved into a startling new form.

The team returns to Earth with a piece of technology that allows them to see alien creatures everywhere, and must attempt to contain the problem when it spreads beyond the base.

Colonel O'Neill is charged with the murder of Senator Kinsey, and the rest of the team must uncover a conspiracy in order to clear his name.

Colonel O'Neill is trapped on an alien planet with Maybourne, and must fight to stay alive as his companion becomes increasingly paranoid.

SG-1 attempts to save a planet's inhabitants from Nirrti's genetic experimentation, but find themselves to be her next victims.

General Hammond and the Pentagon reveal the existence of the Stargate to other world governments, and must defend the fact that the program is operated by the United States military.

When the team finds a crashed ship on another planet, their efforts to help the crew effect repairs are hindered by a group of aliens.

A near-death trial causes Teal'c to imagine his life as very different from the one he knows, where he is a normal person living on Earth until he can no longer distinguish reality.

Prometheus is forced to land on an alien world, where the local Stargate is the team's only chance of returning home though the local population believe the gate to be a myth.

The team finds an impoverished world enslaved by a Goa'uld underlord, but their plans to free it may be compromised when Jonas experiences unexplained visions of the future.

SG-1 is called to defend the people of Abydos from the Goa'uld once again when they learn that Anubis, in search of a powerful device, is about to attack.