Season seven of Stargate SG-1, an American-Canadian television series, began airing on June 13, 2003 on Sci Fi. The seventh season concluded after 22 episodes on March 9, 2004 on British Sky One, which overtook the Sci-Fi Channel in mid-season. The series was developed by Brad Wright and Jonathan Glassner. Season seven regular cast members include Richard Dean Anderson, Amanda Tapping, Christopher Judge, Michael Shanks, and Don S. Davis.
Jonas translates a tablet describing the last city the Ancients were building before the plague, the "City of the Lost". SG-1 visits the planet and finds Daniel, but his memory is gone. They must recover his memories in order to defeat Anubis.
Anubis's superweapon has been put out of commission, but Anubis escapes into hyperspace. Jonas has been captured by Anubis and Daniel is still aboard Anubis's ship, evading capture. Anubis mind probes on Jonas and begins to attack Kelowna.
A teenage boy shows up at the SGC claiming to be Jack O'Neill. He recalls a dream in which an Asgard was studying him. They determine that they must find this Asgard to fix what has been done to Jack.
In a fight with Jaffa, Teal'c is wounded. Without his symbiote, he cannot regenerate. Daniel cannot remember something important, so he goes searching through the logs for any sign of his lost knowledge. Teal'c feels that the Tritonin has made him weak.
On a planet with a toxic atmosphere, there exists a bubble of livable atmosphere. The humans living there tell SG-1 that were industrialized and poisoned the air, but simplified their lives and built the dome; they also have a neural interface.
While investigating a crashed ship, SG-1 finds hundreds of inhabited pods. While counting, they are all knocked unconscious. Upon returning to SGC, Daniel insists on getting back to the ship and appears to not know where he is nor who anyone else is.
At a mining outpost, an unknown foe captures a survey team member. Based on mining artifacts, Daniel thinks the creature is an Unas. When Teal'c finds the missing man as one of a group of corpses warning others away, their suspicions are confirmed.
The captain of the Serrakin prisoner transport ship Cerberus seeks Major Carter's help in winning a race and offers in exchange full access to their ion engine technology. Sam agrees to help and insists upon running the race with him.
Jay Felger and Carter work on a computer virus that disables a DHD by scrambling its symbols and corresponding coordinates. When Daniel, O'Neill and the other SG teams become stranded unable to dial home, Felger's Avenger virus seems to be spreading.
After being saved by a group of free female Jaffa, SG-1 is taken to the females' world to meet their leader, Ishta, who proposes an alliance between her all-female rebel group, Haktil, and the Tau'ri. The Tau'ri offer her Tritonin.
Bra'tac and Teal'c encounter a heavily armed enemy with shielding protecting him from Goa'uld weaponry who killed two Goa'uld's guards. They barely defeat him and bring him back to SGC for study, but this new threat poses a greater Tau'ri problem.
The Tau'ri and Tok'ra have used their captured super-soldier to determine his planet of origin. Though with Daniel, Dr. Lee, and the Ancient device they found in the hands of Honduran kidnappers, SGC must find a way to retrieve them.
Prometheus, with Major Carter as an advisor, encounters an unknown spacecraft, which attacks. Carter is knocked unconscious. She awakes to finds the ship devoid of crew and, as she tries to escape the gas cloud by herself, she begins to hallucinate.
Jonas Quinn returns to SGC to ask for assistance in saving his nation. He explains a large vein of Naquadah has just been affected. The Kelownan scientists believe that the change will cause this deposit to explode taking their entire nation with it.
Maj. Carter has been set up with her brother Mark's friend Pete, a cop from Denver who thinks Carter works for the Air Force. Daniel is being visited in his dreams by his former lover, Sarah, who was possessed by the Goa'uld system lord Osiris.
At the new Alpha site, Major Carter and Selmak (her dad) are working on a new weapon for Anubis superdrones when a fleet of Goa'uld ships attacks. Carter escapes with the prototype weapon but finds herself being pursued by a superdrone.
The president asks a documentarian to film SCG's operations. His arrival is unwelcome and he clashes with the personnel. Nevertheless, he conducts interviews with SG-1 and the SGC scientists. An off-world SG team finds the remains of an Ancient city.
SGC encounters an unforeseen predicament, with half of SG-13 off-world engaging enemy Jaffa, SG teams 1, 5, and 7 go in as backup. O'Neill takes a staff blast to the chest. Many deaths from the encounter hit SGC hard.
Agent Barrett of the NID calls SG-1 to Los Angeles to consult on a mass murder of a rogue sleeper cell by a woman. There they find many Goa'uld artifacts relating to Sekhmet, a subordinate of Ra. How this operation relates to the Goa'uld eludes SG-1.
The Head of the Joint Chiefs of Staff briefs the new President on the Stargate program. Vice President Kinsey attempts to get his running mate to back his policies for the program, but the president decides to look into the situation himself.
SG teams 1, 3, and 5 go off-world to attempt the extraction of an Ancient repository device. Upon arrival, Goa'uld ships fire on SG-1. With no other way to keep Anubis from claiming the knowledge for himself, Jack submits to the dangerous device.
Jack and Daniel attempt to unearth the location of the lost city of the Ancients. Bra'tac, bringing with him the news of an impending attack on the Tau'ri by Anubis, takes Teal'c to help him acquire ships and warriors for the defense of Earth.