A million light years from home, Dr. Daniel Jackson (James Spader), Colonel Jack O'Neill (Kurt Russell) and a crack team of time travelling commandos find themselves trapped in an extraordinary world amongst alien people. They had prepared for danger, they had expected the unknown... but what lay on the other side of the Stargate was beyond their wildest imaginings.
- Children of the Gods
General Hammond summons Colonel Jack O'Neill out of retirement when aliens emerge from the Stargate, kill the soldiers guarding it, and kidnap a female guard. In the aftermath of the attack, O'Neill confesses that he defied the order to destroy Abydos, and that Daniel Jackson is still alive.
- The Enemy Within
Kawalsky, O'Neill's right-hand man, has been having terrible headaches caused by an alien Goa'uld larva that has attached itself to his brain. With guidance from Teal'c, the doctors operate to remove the alien, hoping to get it in time before Kawalsky falls completely under alien control.
On the planet Simarka, the SG-1 team meets the Shavadai, a race of people similar to the ancient Mongols of Earth, who operate by a strict code, which includes second-class status for women. Captain Carter is threatened with death on her first encounter with the Shavadai chief.
- The Broca Divide
The SG-1 team travels to a planet known as P3X-797 and discover a world divided between a dark and light side, with a population similarly split between the Untouched (a Bronze Age people who seem almost like the Minoan civilization of Earth) and the Touched (heavy-browed primitives with limited skills).
- The First Commandment
The SG-1 team is sent through the Stargate after SG-9 is declared missing in action. They discover SG-9 leader Captain Jonas Hanson posing as a god, forcing the inhabitants of the planet to rebuild the giant Goa'uld temples and condemning disbelievers to death by radiation exposure.
- Cold Lazarus
The SG-1 team discovers a valley full of broken crystals. Alone, O'Neill finds a whole crystal with blue light emanating from it. Upon touching it, he is struck down and a duplicate O'Neill appears. The double returns home through the Stargate, with the unsuspecting team.
- The Nox
Under government pressure to discover superior technologies, O'Neill and the team head to a planet Teal'c remembers, which has creatures called Fenri that possess the power of invisibility. They arrive to discover a Goa'uld hunting party, led by Apophis, is already there tracking the Fenri.
- Brief Candle
The team travels to Argos, where they find a civilization of beautiful, happy people who celebrate while the sun shines and mysteriously drop to sleep the minute that it sets. More mysteriously, they seem to age very rapidly - a lifetime is 100 days - an effect that O'Neill unwittingly inherits.
- Thor's Hammer
In search of allies in their battle against the Goa'ulds, O'Neill and the SG-1 team travel to the planet Cimmeria, home to the legendary Norse gods. But, Cimmeria has long ago been declared off-limits to Goa'ulds and when the team emerges from the Stargate, Teal'c is trapped in a mysterious beam of light.
- The Torment of Tantalus
Daniel Jackson makes a remarkable discovery while going through film footage of Stargate experiments conducted in 1945. It seems that the early team, led by Professor Langford, succeeded in getting the Stargate to work, and that a young professor, Ernest Littlefield, actually traveled through the gate, never to return.
The team finds out that Teal'c has a son Rya'c, who has reached the age at which he will receive his Goa'uld larva. Teal'c is determined to stop the process that would make his boy a servant to the Goa'ulds. With a promise to return with a Goa'uld larva for study, the team, disguised as monks, heads through the Stargate.
- Fire and Water
The SG-1 team returns from the planet Oannes in a panic - and without Daniel Jackson, who was last seen being consumed by a column of flames. But, as his comrades mourn him on Earth, Daniel is a captive of an amphibious humanoid creature known as Nem.
When archaeologists exploring a Mayan pyramid in Mexico find a sarcophagus covered in Egyptian hieroglyphics, they accidentally release Hathor, a Goa'uld who has taken on the persona of a powerful Egyptian goddess, awoken from a sleep that has lasted a millennium.
The SG-1 team travels to planet P8X-987, where they discover that a strange disease has wiped out everyone on the planet. Everyone that is, except a little girl named Cassandra. As O'Neill and Teal'c remain on the planet to observe the black hole, Carter and Daniel return to Earth with the girl.
When the SG-1 team travels to P3X-1279, Teal'c recognizes it immediately as Cartago, home to the Byrsa and one of the Goa'ulds' favorite places to harvest humans for assimilation. Teal'c had come here when he was head Jaffa to Apophis. He is remembered by one of the Byrsa, who accuses Teal'c of killing his father.
The SG-1 team arrives on the planet Tollan to find a scene of chaos and death. A volcano is erupting, spewing choking ash and burning lava, and bodies litter the ground around the Stargate. The team gathers up a few survivors and returns through the gate to Earth. The Tollans, however, are not grateful for being rescued.
The Stargate malfunctions, and as a result, Teal'c and Daniel make it back to the SGC, but Jack and Sam find themselves trapped near a Stargate in an icy crevasse on an unknown planet. O'Neill is badly hurt, and Dr. Carter must try to dig the nearby gate device out of the ice and find a way to make it work.
- Tin Man
O'Neill and the SG-1 team arrive on P3X-989, only to be zapped by an electrical trap that renders them unconscious. When they awake, they find themselves in an underground lab with Harlan, a strange but apparently peaceful native of P3X-989 who claims to be 11,000 years old.
- There But For the Grace of God
While exploring an alien complex on P3R-233, a world that appears to have been destroyed by the Goa'uld, Daniel Jackson discovers a slab that, when activated, turns into a shimmering mirror. He touches the mirror and gets a mild jolt but thinks nothing of it until he finds himself in an alternate reality.
Having escaped marauding Goa'ulds in another Earth reality (in There But For the Grace of God), Daniel Jackson warns that it is only a matter of time before they launch an attack in this one. But, the Stargate program faces a more immediate threat - from Senator Kinsey, Chairman of the Appropriations Committee.
- Within the Serpent's Grasp
The Stargate is being shut down by the U.S. government, despite Daniel's warning of an imminent Goa'uld attack on Earth. The SG-1 team, armed to the teeth, defies orders to make an unauthorized trip through the Stargate to what they believe to be the origin of the attack. (Part 1 of 2).
- Serpent's Lair
As a fleet of Goa'uld warships heads towards Earth, threatening to destroy it, the SGC prepares for the worst, sending the best and brightest of American society through the Stargate to another planet. Meanwhile, the SG-1 team have used the Stargate to board a ship commanded by Apophis' son Klorel. (Part 2 of 2).
- In the Line of Duty
The SG-1 team is on a mission to Nasya, hoping to rescue the survivors of an attack by the Goa'uld. During the rescue, Dr. Samantha Carter's body is taken over by a Goa'uld that was hiding in the body of a mortally injured Nasyan. Carter is confined to a cell, while O'Neill bargains with the Goa'uld for her life.
While exploring a seemingly insignificant planet, the SG-1 team is approached by a man who pleads for help. They try to defend him, only to discover that he is a fleeing murderer. By aiding him, they become complicit in his crime, and are sent through the Stargate to a penal world where brute strength and raw power rule.
- The Gamekeeper
The SG-1 team travels to P7J-989, where they discover a beautiful garden and a dome full of strange metallic chambers, each containing an unconscious person. As the team inspects the chambers, they are trapped and knocked unconscious. They awaken to find they are reliving pivotal moments in their lives.
While exploring planet P3R-636, the SG-1 team comes across a troop of Jaffa warriors and ceremonial priests delivering naquadah, an element treasured by the Goa'uld, through the Stargate. What catches Daniel Jackson's eye, however, is the beautiful Princess Shyla, the melancholy daughter of the planet's ruler.
- Thor's Chariot
O'Neill and the SG-1 team return to Cimmeria after learning that the Goa'uld have invaded the planet. The team feels responsible, since on their previous visit they destroyed "Thor's Hammer," the planet's main instrument of defense against the Goa'uld. They make some remarkable discoveries on the planet.
- Message in a Bottle
While exploring a now dead planet, O'Neill and the SG-1 team find an orb that sends out electromagnetic signals. They think it is a time capsule of some sort and are intrigued by its power source, which seems to have lasted for millennia. They bring it back through the Stargate for further study.
Teal'c's mentor Bra'tac arrives unexpectedly through the Stargate with shocking news: the Goa'uld Apophis survived the destruction of his ship and has now kidnapped Teal'c's son, Rya'c. O'Neill and the rest of the SG-1 team agree to join Teal'c as he returns to Chulak to rescue Rya'c.
Daniel Jackson and Teal'c travel back to Abydos, to fulfill the promise made to Sha're's father Kasuf. When they arrive, Daniel learns that his wife, whom he hasn't seen since she was taken by the Goa'uld, is nine months pregnant. The father is Apophis, who plans to use the baby as his new host.
While exploring BP6-3Q1, O'Neill and the SG-1 team are attacked by giant insects. The team escapes through the Stargate, but not before Teal'c is stung. When Teal'c returns to Earth, a strange transformation begins, as the insect virus transforms Teal'c's DNA into something like its own.
- The Tok'ra, Part 1
Captain Samantha Carter has a vivid dream in which she sees through the eyes of Jolinar, a Tok'ra and rebel Goa'uld, who briefly inhabited her body before dying (in In the Line of Duty). Although her father Jacob is dying of cancer, Carter knows she must go on the mission with the rest of the SG-1 team to find the Tok'ra.
- The Tok'ra, Part 2
The Tok'ra have turned down SG-1's request for an alliance against the Goa'uld because, as Garshaw explains, the people from Earth don't offer enough rewards to justify the security breech. And, the fact that none of the humans will act as host for Selmak, a Tok'ra whose host is dying, does little to build trust.
The SG-11 team has not returned from planet PXY-887, where they discovered an element, trinium, that is a hundred times lighter and stronger than steel. Instead, the inhabitants of the planet have fired an arrow made of trinium through the Stargate and into the shoulder of Jack O'Neill.
When a group posing as an SG team steals the climate-controlling Touchstone from the planet Madrona, the planet's weather deteriorates, threatening inhabitants with imminent death unless the device is recovered. Madrona's high priest Roham and his granddaughter princess La Moor, blame the SG-1 team for the theft.
- The Fifth Race
Daniel and the rest of the SG-1 team travel to an ancient room that houses alien inscriptions, in an attempt to decode alien languages discovered by a probe. When O'Neill peers through a viewer in the ancient room, he is caught in its grasp. Shortly after this imposed trance, alien words begin appearing in his speech.
- A Matter of Time
While attempting to save the members of SG-10 from a black hole on planet P3X-451, the SG-1 team activates the Stargate and exposes themselves to the hole's gravitational pull. Trying to break free, the team shuts down the gate's power and in the ensuing explosions Teal'c is badly injured.
When the SG-1 team stumbles upon the chamber of former Goa'uld enemy Ma'chello, they fall victim to his powerful body-swapping invention. Ma'chello takes on Daniel's body and the young archaeologist finds himself trapped in the body of an old and dying man.
- Serpent's Song
Pursued by Goa'uld death gliders, former Goa'uld conqueror and sworn enemy of the SGC, Apophis, throws himself on the mercy of the team. Despite his past evil, SG-1 grants him sanctuary. Apophis, who shows signs of having been tortured, promises all the knowledge of the Goa'uld in return for a new host body.
- One False Step
During a routine reconnaissance mission, the UAV plane crashes into a cactus-like plant on a planet inhabited by an unusual life form. Sent to recover the plane, the SG-1 team discovers those living on the planet are falling ill, and before long a plague of illness sweeps the race.
- Show and Tell
A young boy arrives at the SGC with his mother, a member of the invisible Reetou race. He says the Goa'uld destroyed their home planet, and now Reetou rebels intend to kill all humans. The rebels think that by killing all potential hosts for the Goa'uld, they will eliminate the Goa'uld themselves.
Because of a solar flare, the SG-1 team is propelled back in time to 1969, landing in a top-secret military facility. As the team is transported for further interrogations, a young Lieutenant Hammond helps them escape. They must then race to the Stargate before their only chance of leaving the past is gone forever.
- Out of Mind
Wakening from what seems like cryogenic suspension, O'Neill finds himself in a futuristic version of the SGC. He is told by doctors he has been frozen for 79 years, and the rest of the SG-1 team perished long ago. The doctors hook O'Neill to a device which turns his memories into holograms. (Part 1 of 2).
- Into The Fire
Trapped on Hathor's planet, Carter and Daniel can only watch helplessly as Hathor implants O'Neill with a Goa'uld symbiote. General Hammond sends Colonel Makepeace and six Stargate units to reclaim SG-1, but when the units are defeated, Hammond decides to do the job himself. (Part 2 of 2).
Carter's father, Jacob, enlists the SG-1 team in his hunt for the ancient Goa'uld Lord Seth, whom he believes is hiding on Earth. A computer search reveals Seth has maintained power on Earth for thousands of years using false religion, and the SG-1 team trace him to a heavily armed compound in Washington state.
- Fair Game
Asgard leader, Thor, tells O'Neill that the Goa'uld System Lords plan to attack Earth, and offers help in negotiating a peace deal. Three System Lords attend the session, Yu, Nirrti, and Cronus. The three initially agree to the Asgard's peace proposal, on the condition that Earth gives up the Stargate.
During a routine mission, the SG-1 team discovers a room containing the corpses of a league of Goa'uld who challenged the System Lords. One is holding a tablet, and after Daniel touches it, he begins to hear voices and see nightmarish visions. Medical tests indicate schizophrenia.
- Learning Curve
In the pursuit of knowledge, Jack O'Neill, Teal'c, and Daniel Jackson travel to the planet Orban as part of an exchange program. O'Neill and the rest of SG-1 soon discover that the children on this planet are used to acquire knowledge for the entire population, then discarded.
- Point of View
The SGC is taken aback when an alternate reality version of Samantha Carter and the deceased Major Kawalsky are found in top secret Area 51. To transport themselves to our reality, they used the quantum mirror (last seen in season one's There But For The Grace of God).
- Dead Man's Switch
SG-1 travels to planet PJ6-877 for a routine exploration. Almost immediately after arriving, they are captured in an invisible force-field by alien bounty hunter Aris Boch, who is hunting a Goa'uld wanted by the evil System Lord Sokar. He attempts to solicit help from SG-1, in exchange for their freedom.
SG-1 arrives at a medieval village and frees Mary, a young woman who has been left outside tied to a stake. Simon, friar of the village and Mary's friend, explains that Mary is a sacrifice for the demon that plagues their village. The Canon chose her when he mistook her illness for evil possession.
- Rules of Engagement
Upon exiting the Stargate, SG-1 finds itself in the midst of battle. A group of SG soldiers battles a Jaffa army. Believing the soldiers to be the missing-in-action SG-11 team, O'Neill and the others provide assistance. Much to their surprise, the mystery SG team turns their weapons on SG-1.
- Forever in a Day
As SG-1 attempts a rescue of captured Abydonians, Daniel sees his long-lost wife Sha're watching the activity from a nearby tent. He follows her inside, where Sha're, who is actually the Goa'uld Amonet, takes Daniel in the grip of a Goa'uld ribbon device. Teal'c enters the tent with his staff weapon as Daniel falls unconscious.
- Past & Present
SG-1 travels to a planet whose inhabitants seem to be suffering from mass retrograde amnesia. They have no memory of their lives before the unknown event they call the "Vorlix", and report that their elders and children are missing. The planet faces complete devastation unless the people's memories can be restored.
- Jolinar's Memories
The Tok'ra Martouf arrives at the SGC with troubling news: Major Carter's father, Jacob, and his Tok'ra symbiote Selmak, have been captured by the evil Goa'uld System Lord Sokar. Jacob/Selmak is imprisoned on a moon called Netu, which Sokar has transformed into a literal Hell. (Part 1 of 2).
- The Devil You Know
During an attempt to rescue Jacob Carter, SG-1 and Martouf have been captured by Apophis, now one of Hell's denizens, who is determined to use their information to overthrow Sokar. With Tok'ra memory technology and a hallucinogenic drug, each prisoner is forced to relive vivid, painful memories. (Part 2 of 2).
On their return from a mission, SG-1 learns that part of the SGC has been sealed off due to a chemical leak. Soon after, Dr. Fraiser injects each member of the team with a sedative, rendering them unconscious. Teal'c is the first to awaken, and secretly observes Dr. Fraiser and General Hammond talking with two aliens.
The Tollan Narim pays an unexpected visit to the SGC, inviting the members of SG-1 to participate in "Triad." When SG-1 shows up on the new Tollan home world, they learn that the Triad is an ancient ceremony of justice, and the person on trial is their old friend Skaara.
SG-1 steps through the Stargate on their way to a paradise planet and end up back at the SGC. Adding to their confusion is Hammond's assertion that the team was gone for fifteen hours. An analysis of the MALP data reveals a brief initial image of an alien lab just before the paradise view.
- A Hundred Days
Colonel O'Neill and the rest of the SG-1 team have established ties with a small village on the planet Edora, and their leader Laira, with whom O'Neill shares a mutual and quiet attraction. Everyone gathers to watch the annual meteor shower referred to by the natives as "fire rain."
- Shades of Grey
SG-1 travels to Tollana to negotiate a trade. O'Neill becomes annoyed when the Tollans refuse to cooperate due to their fear that any weaponry given to Earth would likely be used on itself than against the Goa'uld. In an act that shocks the rest of his team, O'Neill steals a Tollan device as they are departing back to Earth.
- New Ground
The team travels to a planet where the planet's two cultures have been at war over their opposed beliefs regarding the Stargate. Upon their arrival, they are met by the curious Nyan, a scientist who explains that their arrival proves that the beliefs of his rival culture, the Optricans, is true.
- Maternal Instinct
Using the combined knowledge of Bra'tac, Daniel, and computer analysis, SG-1 finds the planet most likely to be "Kheb", of Jaffa and Goa'uld legend. Bra'tac and SG-1 travel to the planet in search of the Harsesis child, the child Apophis fathered with Sha're/Amaunet, in a race to find the child before Apophis.
- Crystal Skull
Jackson becomes intrigued when the video transmission from the MALP reveals a huge Mayan pyramid with a glowing crystal skull in its center. He tells the rest of SG-1 and General Hammond that the skull appears to be identical to one his grandfather, Nicholas Ballard, found in Belize in 1971.
O'Neill is suddenly transported aboard Thor's ship, where he begins to hear a strange sound and moments later is faced with hundreds of menacing looking metallic bugs. He learns that these bugs are called replicators and are artificial organisms that have overtaken the ship and directed it toward Earth. (Part 1 of 2).
- Small Victories
O'Neill, Carter and Teal'c return to Earth. Soon after, O'Neill and Teal'c must risk their lives to keep the Replicator bugs from gaining a foothold on Earth. Meanwhile, Major Carter goes to an Asgard planet to help Thor find a way to defeat the Replicators which are attacking an Asgard planet. (Part 2 of 2).
- The Other Side
The SGC receives a distress signal from another planet, which seems to have ties to Earth. The people on the planet are facing extinction at the hands of their enemy, and need our help. SG-1 gates to the planet to offer aid, but as the situation grows more dire, they discover not all is as it seems.
A Tok'ra scientist brings a phenomenal new technology to the SGC: armbands that give the wearer greatly increased strength and speed. They were built by a race called the Atonieks, a now extinct species that predates even the Goa'uld. Guest starring Vanessa Angel as Anise/Freya.
The SGC plays host to a woman from Teal'c's past, a Jaffa who claims she has succeeded in communicating with her symbiote and convincing it to turn against the Goa'uld. If true, the symbiote could offer up a wealth of information. Guest starring Vanessa Angel as Anise/Freya.
- Divide and Conquer
When a member of the SGC goes crazy and attempts to kill a Tok'ra official, it is revealed that he was the victim of a Goa'uld mind control process that programs individuals for violent, suicidal acts. The Tok'ra test the rest of the SGC personnel for other victims. Guest starring Vanessa Angel as Anise/Freya.
- Window of Opportunity
The SGC is trapped in a temporal anomaly, but only Jack and Teal'c seem to be aware of the fact. They are faced with the dual task of convincing everyone that they're reliving the same six hours over and over again, and trying to find a way to break the time loop.
A chance discovery on the ocean floor gives the Russians access to Stargate technology. But when the a Russian scientist turn to the SGC for help, the SG-1 team is led to a remote military installation in Russia - and an unnerving mystery. Guest starring Marina Sirtis as Dr. Svetlana Markov.
- The First Ones
While on an archeological expidition on an alien world, Daniel Jackson is captured and held prisoner by an Unas (see season 2's Demons), and must use his many skills in order to survive. The rest of the SG-1 team go in search of him, but soon run into trouble themselves.
- Scorched Earth
SG-1 is caught in a conflict between two civilizations trying to colonize the same planet. The current inhabitants face destruction by the new visitors. SG-1 studies the situation, and concludes that the visitors' vessel is terraforming the planet for a type of life unlike any they know - sulfur-based life, rather than carbon-based.
- Beneath the Surface
After visitong a world experiencing an ice age, the minds of Colonel O'Neill and the rest of the SG-1 team are erased by the ruling elite of the planet. They are then used as forced labor in an underground alien facility, under new identities that have been created by their captors.
- Point of No Return
SG-1 becomes aware of a conspiracy theorist who has heard rumors about the Stargate. Not only that, but he thinks he's an alien and claims to have vague memories of an alien life. The SG-1 team goes to Montana to investigate this seemingly ludicrous threat.
Using two recovered Goa'uld death gliders, Area 51 personnel have created a hybrid vessel that looks like a Goa'uld death glider on the outside, and a jet plane on the inside. Colonel O'Neill and Teal'c take the new craft out for a simple test, but they are soon marooned in space.
- The Curse
Daniel discovers that his mentor, Dr. Jordan, was killed in a lab explosion while analyzing the Osiris Jar, an artifact recently recovered from a "cursed" 1931 expedition to Egypt. Jackson travels to Chicago to attend the funeral and see his friends and former collegues again.
- Serpents Venom
When Apophis and Heru'er decide to enter into an alliance, SG-1 must try to stop them. Teal'c goes to Chulak in an effort to recruit some of his fellow Jaffa warriors to help fight the Goa'uld. On Earth, Jacob Carter and the SGC receive a transmission from the Tok'ra through the Stargate.
- Chain Reaction
The SG-1 team must adjust to a new commanding officer, because General Hammond decides to step down as commander of the SGC. Shortly after, O'Neill discovers foul play behind the general's resignation, and he must team up with a former enemy to get to the bottom it.
Ten years into the future, Samantha Carter and Doctor Fraiser have discovered a dark secret that threatens the entire human race. The former members of SG-1 must again team up in order to send a message into the past, hopefully to prevent this terrible disaster.
- Absolute Power
In an almost magical whirlwind, Daniel is reunited with the Harsesis child, Shifu (last seen in the season 3 episode Maternal Instinct). The child teaches Daniel a lesson by giving him some Goa'uld genetic memories and launching him on a spiritual journey. Daniel soon begins to behave erratically.
- The Light
Lieutenant Barber of SG-5 unexpectedly commits suicide by jumping into a wormhole vortex. While investigating the cause of Lt. Barber's suicide, the SG-1 team travels to a planet where they find a Goa'uld pleasure palace, and they become transfixed by a beautiful, deadly device inside.
Carter tries to motivate a brilliant, but rebellious student by taking her through the Stargate. But a routine excursion takes a deadly turn when they are attacked by beings of pure energy. The colonel orders everyone back to the Stargate for an immediate evacuation, but a swarm of the life forms block their path.
The SGC makes contact with a world whose address was taken from the Ancients' repository of knowledge, and sends through a MALP probe. An alien virus infiltrates the SGC computer and gathers classified data. When the virus is presumed killed, it is learned that it has actually sought refuge in Carter's body.
- Double Jeopardy
The SG-1 team encounters the Goa'uld System Lord Cronus (who previously appeared in Fair Game and Crossroads) while trying to undo a mistake they supposedly made on a prior mission. They confront Cronus with help from an unexpected source.
As SG-1 helps to evacuate the Tok'ra from the planet Vorash to a new base, matters are complicated when a spy reveals their location to Apophis. The team attempts a daring plan to take out the Goa'uld's powerful fleet, but the captured spy soon escapes, jeopardizing their plan. (Part 1 of 2).
The SG-1 team, in their stolen Goa'uld mothership, has arrived in another galaxy, 125 years travel from Earth. Shortly after their arrival, Apophis' mothership arrives, carrying Teal'c, who had been shot with a staff weapon, and is presumed dead. As Apophis begins to attack, an unknown third ship arrives. (Part 2 of 2).
His mind altered by Apophis, Teal'c must undergo an ancient ritual that takes him to the edge of death itself, in order for him to rediscover who he is. With assistance from Bra'tac, Teal'c is forced to relive several episodes from his life, from when he was still loyal to Apophis, while O'Neill, Carter, and Jackson sit by his side.
After arriving on an alien planet for a routine survey mission, Samantha Carter passes out for no apparent reason. After returning to Earth, she takes some time away from the SGC, and unexpectedly finds herself in the company of a strange new friend. Guest starring Sean Patrick Flanery and John de Lancie.
- The Fifth Man
Colonel O'Neill and Lieutenant Tyler are ambushed by Goa'uld forces and trapped behind enemy lines, fighting a new Jaffa faction under an unknown System Lord. Meanwhile, the rest of SG-1 discover that they don't know who Lieutenant Tyler is. Guest starring Dion Johnstone and John de Lancie.
- Red Sky
SG-1 visits a new world populated by people who very much resemble the Amish in their way of life. Unfortunately, activation of the Stargate causes a variation in the sun's radiation. Thus, all life on the planet will soon die. The Asgard, who are the protectors of this world, are absent again for some unknown reason.
- The Rite of Passage
Cassandra, who has been under the supervision and care of Dr. Fraiser, begins to have attacks of uncontrollable telekinesis, and her health deteriorates rapidly. Because of this problem, the SG-1 team travels back to her home world, to try and find something that can help her.
- Beast of Burden
The Unas (last seen in Season 4's The First Ones) have been made slaves by a group of humans, and SG-1 is put in the position of having to decide if they are morally obligated to liberate the Unas from bondage. Daniel gets very personally involved, and at the end of the day the seeds of civil war are sown.
- The Tomb
SG-1 must reluctantly team up with a Russian unit, on an off-world mission to investigate the disappearance of a rogue Russian Stargate team led by Major Valentine Kirensky. Dr. Jackson attempts to open the doorway and gain access to the inside of a Ziggurat structure, which is believed to be 3000 years old.
- Between Two Fires
The fate of Tollana hangs in the balance as the SG-1 team strives to solve a mystery on the Tollan home world. Colonel Jack O'Neill tries to discover the motive behind the Tollans' sudden decision to share weapons technology with SG-1, contrary to their behavior in the past.
SG-1 encounters a new world and a potential new ally in the war against the Goa'uld, though they do not yet know the Aschen's dark secret. SG-1 finds out that these people might very well be the ones that the future O'Neill may have been warning them about. (The Aschen were first seen in season 4's 2010)
- Desperate Measures
When Major Samantha Carter is abducted by a mysterious man in black, General Hammond authorizes Colonel Jack O'Neill and Daniel Jackson to go out and find her. The two men track Major Carter to a hospital where dangerous experiments are being conducted.
- Wormhole X-treme!
Martin Lloyd (last seen in season 4's Point of No Return) pitches a script to a television studio, which reads suspiciously like the Stargate scenario. Colonel Jack O'Neill is sent to confront him. Stargate SG-1's entire team of writers and producers worked together to pen this special 100th episode.
- Proving Ground
While training Air Force cadets at a top-secret facility, Colonel O'Neill learns of a possible alien incursion at Stargate Command. Knowing that other SG teams may be compromised, he has no choice but to take his young troops into a very real and very dangerous battle situation.
- 48 Hours
As the SG-1 team travels to Earth through the stargate, Teal'c is lost in transit, failing to materialize at Earth's gate. Carter tries to figure out a way to bring him back safely. Meanwhile, Daniel negotiates with the Russians for their help, and O'Neill uses his own sources to try and find the answer.
The Tok'ra learn that the Goa'uld System Lords are negotiating an alliance, and request Daniel Jackson's help to infiltrate the meeting. Meanwhile, the other members of SG-1 help the Tok'ra to evacuate their base, and Samantha Carter makes a surprising discovery. (Part 1 of 2).
- Last Stand
With time running out to complete his plans to release the biological weapon supplied by the Tok'ra, Daniel Jackson is confronted by Osiris, and he must come up with a new plan. At the same time, an attack force led by a mysterious Goa'uld approaches the Tok'ra home planet. (Part 2 of 2).
- Fail Safe
Earth finds itself threatened by something even larger than the Gou'ald, when they learns that an asteroid is on a collision course with the planet. With no luck getting help from the Tok'ra or Asgard, the team must put together a plan to solve the problem on their own.
- The Warrior
A charismatic Jaffa leader tries to rally his people against the Goa'uld, and seeks to forge an alliance with Earth. The SG-1 team travels to the planet with weapons and supplies, but encounters some resistance from both the people on the planet and from within their own ranks.
SG-1 discovers a world that seems to have been destroyed by Replicators, where they find a young girl who may hold the secret to the salvation of the Asgard. After returning to the SGC, they make a very surprising discovery which has the potential to save them or kill them.
- The Sentinel
After another SG team runs into trouble on a mission, the SG-1 team sends a UAV to the planet to investigate, and learns the Goa'uld have arrived there. O'Neill must turn to a pair of convicted criminals for help repairing an alien device, in order to save the world from annihilation by the Goa'uld.
An alien civilization is threatened with extinction when they attempt to build a weapon of mass destruction, exposing Jackson to a massive dose of radiation in the process. When SG-1 visits the planet to investigate, one of the scientists from the planet comes forward with disturbing information.
The SGC is contacted by the Asgard, who inform them that Thor has been killed by the Goa'uld, and they need help to rescue a stranded Asgard scientist. The team discovers that Thor is alive, but he has been captured by Osiris and she is about to discover the secret Asgard laboratory.
- Redemption (1)
Tragedy reunites Teal'c with his son Rya'c, who blames Teal'c for his mother's death. O'Neill and Carter launch a risky plan with untested technology when Earth is attacked by the Goa'uld, while Jonas Quinn tries to prove to O'Neill that he is worthy of being a member of SG-1.
- Redemption (2)
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 Teal'c and Bra'tac on a dangerous mission to destroy the Goa'uld weapon. Meanwhile, O'Neill carries out a plan devised by Quinn.
An abandoned Goa'uld mothership has mysteriously arrived near Earth. The SG-1 team, with the assistance of Jacob Carter, embark on a mission to board the ship and find out its origin. Things quickly go wrong, and they must escape the doomed vessel when it crashes into the ocean.
A team of scientists, working in the ice where the second Stargate was discovered in Antarctica (back in Season 1's Solitudes), uncover a woman frozen in the ice. The SG-1 team travels to Antarctica to aid in the investigation, but they are soon infected with a mysterious disease.
Major Carter, Teal'c and Jonas Quinn investigate the disappearance of a scientist with apparent connections to the Goa'uld. While looking for answers in the small town where he lived, they discover that the town's inhabitants are part of some kind of strange secret experiment.
When Colonel Jack O'Neill is captured and tortured by the Goa'uld, he must rely on an old friend to survive. Meanwhile, the rest of the SG-1 team attempt to find O'Neill's location and mount a rescue mission.
Guest starring Michael Shanks.
- Shadow Play
Jonas Quinn's people come to Earth to ask for aide in an impending war on their planet. SG-1 discovers that they are planning to use a weapon of mass destruction in a preemptive strike against their enemies, and must be stopped. Guest starring Dean Stockwell.
- The Other Guys
During a seemingly normal archaeological expedition, the SG-1 team is captured by the Goa'uld. A pair of bumbling scientists decide to mount a rescue operation without permission from the SGC, even though they were ordered back to Earth. Guest starring John Billingsley as Coombs.
On Earth's new offworld base, which has also become a refuge to the rebel Jaffa, a group of Tok'ra arrive after being attacked by the Goa'uld. Almost immediately, tensions arise between the Tok'ra and Jaffa, when it is discovered that someone has been murdering people in the camp.
A recently discovered alien world offers Earth a medicine with the power to cure any illness, but as Major Carter, Teal'c, and Jonas Quinn investigate events on the planet (with the assistance of the Tok'ra), they discover that the hidden price for this wonder drug may be too high to pay.
- Prometheus (1)
A news reporter threatens to expose a top-secret military project, but when SG-1 gives her a tour of the new X-303 space ship, they discover that she is a pawn in a much larger plot involving Colonel Simmons and Adrian Conrad. (Part 1 of 2).
- Unnatural Selection (2)
Still on the ship Prometheus, the SG-1 team is visited by Thor. He informs them that one of the Asgard planets has been overrun by Replicators, and the Asgard need their help to defeat the invaders.
(Part 2 of 2).
- Sight Unseen
After returning from a desert planet with an artifact believed to be a product of the Ancients, personnel at the SGC begin to see strange creatures. It is up to Carter and Quinn to deactivate the strange device, while O'Neill tries to stop the spread of the effect outside of the base.
- Smoke & Mirrors
Upon his return from a vacation to Minnesota, O'Neill is charged with the murder of Senator Kinsey in Washington D.C. Meanwhile, on orders from Hammond, the rest of the team must uncover a government conspiracy in order to clear his name, with help from an unexpected source.
- Paradise Lost
Maybourne touches base with Jack and convinces him that he knows the location of an alien weapons cache. The SG-1 team investigates, but can't work around the impenetrable entryway. Maybourne talks his way into helping out, but double-crosses Jack and leaps through an energized gate.
SG-1 discovers that Niirti, in an attempt to create the perfect human host, is mutating the inhabitants of an unexplored planet with a machine that rearranges their DNA. O'Neill must find a way to escape before he and SG-1 are subjected to the same fate.
General Hammond and the Pentagon are forced to reveal the existence of the Stargate to other world governments. Playing off fears that the US military has too much control, Senator Kinsey suggests that General Hammond be relieved of his command.
Exploring an off-world planet, SG-1 discovers a crashed ship and three human survivors who claim to be under constant attack from hostile aliens. While carter helps repair the ship's computer, she learns that the survivors are hiding a secret...and things may not be all they seem.
- The Changeling
Teal'c mysteriously begins to lose his grip on reality and is haunted by visions of an alternate existence where her is a normal human being. As his paranoia deepends, Teal'c must rely on the help and comfort of his old friend Daniel Jackson.
The team is forced to land on an alien world, where the local Stargate is their only chance of returning to Earth. However, the local government refuses to acknowledge their Stargate's existence.
SG-1 gates to a planet where the people are mining naquadah for the Goa'uld Baal. Their leader, Ellori, asks the team's help to free his people from their oppression. As the team tries to help the locals do this, Jonas starts having strange visions.
- Full Circle
SG-1 must defend the people of Abydos from the Goa'uld once again when they learn that Anubis is about to attack.
Alexis Cruz as Skaara, Michael Shanks as Daniel Jackson.
- Fallen (1)
The SG-1 team discovers Daniel Jackson alive and living on an alien world, but he has no memory of who he is.
(Part 1 of 2.)
- Homecoming (2)
The team returns to Jonas' homeworld when they learn that the Goa'uld are after its naquadria.
(Part 2 of 2.)
- Fragile Balance
A young teenage boy arrives at the SGC and tries to enter using Colonel O'Neill's pass card. He insists that he really is Jack, and that he just woke up small that morning. Grown-up Jack can't be found anywhere.
Teal'c and SG-1 must risk everything to rescue his son and his mentor from a Jaffa prison.
The SG-1 team encounters a planet with a society that has lived for centuries within a computer-controlled environment within a bubble. Outside, the rest of the world is a toxic wasteland.
When SG1 goes to a barren planet, they investigate an abandoned ship full of frozen bodies. The mission goes awry when Daniel's body is 'hijacked' by aliens whose own bodies are gone, but their personalities were stored in a databank.
- Enemy Mine
The team helps out when a mining team runs into trouble off-world. Ultimately, they must summon an old friend to help deal with a potentially explosive situation.
- Space Race
SG-1 helps an alien spacecraft compete in a race, but soon learn that there may be more at stake than the finish line.
- Avenger 2.0
Felger from Season 6's The Other Guys returns, and teams up with Carter to solve a problem of cosmic proportions.
The team finds a fugitive colony of Jaffa women, who must prey on other Jaffa to acquire symbiotes.
Guest starring Star Trek Enterprise's Jolene Blalock as Ishta.
- Evolution (1)
Daniel and another archeologist are taken hostage when they travel to the jungles of Honduras to find an ancient alien device. O'Neill, Carter and Teal'c investigate the appearance of a powerful new enemy.
(Part 1 of 2.)
- Evolution (2)
Jack O'Neill and a former fellow soldier travel to the jungle to attempt a rescue of Daniel Jackson.
(Part 2 of 2.)
Samantha Carter travels to retrieve the stranded Prometheus (last seen in Season 6's Memento). On their way back to Earth, she and the crew run into trouble.
Jonas Quinn seeks help from Earth in avoiding the total destruction of his planet.
Samantha Carter begins a relationship with a detective, from whom she must hide her life at Stargate Command. Daniel comes face to face with the Goa'uld who has taken his former girlfriend as a host.
- Death Knell
Earth's secret offworld base is discovered by the Goa'uld -- and Major Carter goes missing.
- Heroes (1)
A film crew arrives to document the work of the SGC, but may capture more than they planned for when SG-1 is called into action.
Guest Starring Adam Baldwin as Colonel Dixon, Saul Rubinek as Emmett Bregman, Ronny Cox as Senator Kinsey. (Part 1 of 2.)
- Heroes (2)
Stargate Command comes under investigation after an off-world rescue mission goes terribly wrong.
Guest starring Adam Baldwin as Colonel Dixon, Saul Rubinek as Emmett Bregman, Robert Picardo as Agent Woolsey. (Part 2 of 2.)
SG-1 investigates when the NID becomes involved in genetic research.
The newly-elected president must be informed about the Stargate program, and Kinsey makes a new play for control of the program.
Guest starring Robert Picardo as Agent Woolsey, Ronny Cox as Kinsey.
- Lost City (1)
The SGC suffers a shocking upheaval when the White House becomes directly involved in saving the world.
Guest starring Jessica Steen as Dr. Elizabeth Weir.
(Part 1 of 2.)
- Lost City (2)
Anubis begins an assault on Earth, and the planet's only hope of salvation depends on whether SG-1 can find the Ancients' mythical Lost City.
Guest starring Jessica Steen as Dr. Elizabeth Weir.
(Part 2 of 2.)