Ry'ac convinces Teal'c to take him with him and Bra'tac on the mission to stop Anubis, and proves himself very useful when Teal'c and Bra'tac get captured! McKay, is brought back to try and help Sam to find a way to save the stargate and the SGC. The Russian liaison is insisting he have the plans for the X 302 and to have a Russian as part of SG-1. McKay's idea makes the radiation build up even quicker but then Jonas & Sam come up with an idea to remove the Stargate from the SGC and fly it away from Earth so it won't do any damage when it explodes, and Jack has to fly a stripped down X 302 with the Stargate strapped to it. Unfortunately there is not enough power to reach escape velocity so it starts falling back to Earth. A final idea is to do a very short burst so the hyperdrive engine can send the stargate well away from earth. Jack manages this and ejects and SGC is going to close down again, they have no gate and Anubis still has the weapon. Then Teal'c and Bra'tac come back and tell them they have destroyed Anubis's weapon, the US lease the Russian's Stargate, but they also have to give them the plans for the X 302 and say they can have a member in SG-1. Jack says why not give them their own team and he already has a replacement for Daniel in mind, thus Jonas becomes the new member of SG-1.

SG-1 investigate an abandoned Goa'uld ship orbiting Earth. While trying to salvage teh ship, saboteurs attack and the vessel plummets to Earth, deep into the ocean, with O'neill and his crew trapped inside, and time running out.

A frozen female alien that might pre-date human evolution by 50 million years is discovered in Antarctica near the place where the second gate was found. She might, in fact be part of the race that invented the Stargate. After SG-1 manages to thaw her back to life, they discover she may be the source of a deadly virus which infects all humans there. However, she is able to save them by healing them, however in the process she weakens herself, and if she continues to heal them, she could die as well.

When a scientist working on stem cell research disappears, Carter, Teal'c & Jonas investigate and discover that the scientist's town is infested with Goa'uld who can only control the townspeople by night. Will Carter, Teal'c and Jonas be taken over next?

After the events of Frozen, O'Neill is blended with a symbiote to save his life, however it turns that O'Neill influences it to do something it would never have done, and without the knowledge of O'Neill, he tries to save a girl, however he is shot in the process.

Meanwhile, back at SGC, Hammond wants to know where Jack is but the Tok'ra don't know. Thoran the Tok'ra Ambassador tells them that Kanan left and they don't know where he is. Hammond and SG1 insist on getting information on Kanan's mission logs, Thoran not keen on giving the logs to them, is held until the Tok'ra complies.

Jack is captured and being tortured by Ba'al, one of the minor System Lords who was doing research on weapons and gravity at a secret base. He keeps torturing Jack trying to get information from him about his symbiote but Jack can't remember so he kills Jack and then revives him in a sarcophagus. Whilst in his cell, Jack is greeted by Daniel who offers him a chance to ascend, however, Jack isn't ready to die, and asks for his help, however, Daniel tells him that he cannot as the others are watching.

Meanwhile back at SGC, the other members of SG1 start getting "flashes of inspiration". They figure out Jack must be on the planet with Ba'al as Kanan was there as a minor Goa'uld and got lots of information from Ba'als Lotar, his highest ranking slave. Sam figures that when Kanan merged with Jack Jack's personality rubbed off and Kanan felt guilty leaving the Lotar behind and so they've gone to rescue her.

Unfortunately the planet is heavily fortified and Hammond says they don't have enough fire power. Teal'c, during Kel'noreim, thinks of a way to help, let Yu know about the secret base so that he will destroy it, letting him know to blow out the power generators first. Thus giving Jack a fighting chance.

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. They soon discover that the Kelownans have successfully created a Naquadria bomb, but things turn bad when they realise that the professor is under the influence of Naquadria poisoning.

SG-1 is baby sitting a group of scientists who are investigating some old Goa'uld equipment, including the rings when SG-1 get captured by a group of Jaffa, Two of the scientists, Coombs and Felger, decide to rescue them, thinking that they would be hero's like SG-1. Coombs and Felger manage to get the ring device working and ring up to the Jaffa's ship. Unfortunately, when they get there SG-1 aren't too happy to see them as it turns out to be a ploy, created so they can meet with an under-cover Tok'ra operative. However whilst they are hiding Coombs and Felger witness two Jaffa soldiers who are loyal to the Tok'ra being killed, and realise that the Tok'ras cover has been blown. It's now up to the scientists to save SG-1 for real before Apophis comes.

Tensions rise between Earth's allies when the SGC's off world base becomes a refuge to the Tok'ra and rebel Jaffa. The two groups are brought onto the Alpha base, however things start to go wrong when Jaffa and Goa'uld start turning up dead. At first the two are quick to blame each other, however, with the help of the Tau'ri they are able to realise that its the job of an Ashrak (Goa'uld Assassin sent to kill Tok'ra). They realise that to stop it the three races must work together.

SG-1 actually make contact with a friendly race (the Pangeran's) who seem to have created the cure for all disease, called Tretonin. They're willing to trade the medicine with the people of Earth in exchange for gate addresses, however the gate addresses they seek are of Goa'uld occupied worlds.

SG-1 soon discover that the using Tretonin is not without consequences, and that using the Tretonin destroys your immune system similar to the effects of a Jaffa carrying a symbiote. Most of the population of the Pangeran race are dependant on the Tretonin. In an effort to find a secret that the Pangeran's seem to be hiding Teal'c and Jonas discover the source of the miracle cure. They discover a queen Goa'uld as the source of the drug, and realise that the medicine is nothing but ground Goa'uld, and as the queen is dyeing they require a new queen or most of the Pangerans will die.

When one of the immature symbiotes takes over one of the Pangeran they realise something is wrong with the queen as the symbiote has no memory of the queen. The Tok'ra are called to remove the symbiote, but soon realise that the queen is none other than their queen, the founder of the Tok'ra.

When a Press reporter approaches Sam and threatens to go public with information regarding huge amounts of cash being used to fund something known as Prometheus, SG-1 send in Colonel Davies to get them to try and stop the story. He are successful in doing so, however must agree to one condition, they must allow the crew to visit Prometheus and take video's so when it is finally revealed they can get the first rights, and in the meantime the tapes would be in the possession of the Pentagon.

As agreed, Sam and Jonas give the reporter a tour of the new ship, however what they didn't anticipate was that the filming crew have ulterior motives. Soon they take over the ship and threaten to blow the ship up (and along with it destroying half of Nevada) by overloading the engines unless their demands are met.

They soon realise that the crew are working for Simmons and demand he and the Goa'uld in the body of Adrian Conrad are released. SGC reluctantly release the two thinking that the ship will never be able to get far as the hyperdrive isn't fixed, however with the help of the Goa'uld they are able to fix the engine in not time.

However, before they go to hyperspace, Jack and Teal'c are able to take a glider and land on the ship unknown to the crew. They are able to recapture the ship, however, they find Adrian Conrad dead, killed by simmons, only to find the Goa'uld has taken over Simmons. They are finally able to kill the Goa'uld and simmons, however things turn a lot worse when they realise that they don't know where the hyperdrive engines have taken them.

Thor has arrived to help SG-1 in the predicament, and to tell them that his home planet has been overrun by replicators. They had set a trap for the replicators using technology from the creator of the Replicators the android Reese, to call all the Replicators to a planet in the Asgard home system and there they were going to slow down time on the planet so they would have time to find a way to get rid of the Replicators. The trap failed as the device didn't go off as they hoped, in fact they the replicators must have found the time device as now time on the planet is going much faster than in normal time, the Asgard are worried.

As Prometheus is a ship of inferior technology the replicators will not touch it so Thor asks that SG-1 travel to the planet and activate the device as they wanted. O'Neill checks it out with his superiors, and while he's making up his mind Thor tows their ship and gets supplies from Earth and takes them to the Replicator overrun planet.

As they land, SG-1 can see nothing but a single landform. They soon realise that the replicators have consumed everything as they have had 100s or 1000s of years due to the time device speeding up time on the planet. Even the floor of the planet is made from replicator bits. As they go inside the only landform on the planet they find the time device.

Carter attempts to reverse the effects again, however, some humanoids come up to the team, and tell SG-1 to stop. They soon discover that the humanoids are in-fact replicators themselves. They say they want to make friends and put out their hands to shake, O' Neil reluctantly shakes hands with the leader. The replicator instead squeezes his hand and puts his other hand into O' Neill's head! He then accesses O' Neill's memory. The team wake up to find themselves back on their ship. As they try to find out what the replicators did they find a replicator on their ship.

They find out that this certain replicator is 'flawed' and is more human then the rest, he was built the way that Reese should have been built, without what the humans consider the flaw, but the Replicators feel it makes them weaker. The Replicators intend to use SG-1 to find out all about humans and other races and then go out and conquer the Universe!

The Replicators go into SG-1s mind again and the 'flawed' Replicator and Carter devise a plan to get off the planet. When the team wake up again they see that the flawed replicator has made the necessary changes to the time devise. Carter quickly goes to set the time and asks O' Neill how long to set it for. He says 5 but silently tells her to do 3 minutes with his hands. Carter sets it for 3 minutes and tells the replicator to come to the ship just after 3 minutes so the others don't find out that they are gone. Obviously within that time the device would be active and their ship would be off the planet leaving him behind.

The leader of the replicators comes as soon as the engines start up and asks the flawed replicator where the team have gone. First tells Fifth that its a trap and they will leave him. Fifth trusts Carter but does look at the timer just as it reaches 3, and before he has time to stop the timer, it goes to 0 and time slows down.

Meanwhile the team are in orbit of the planet and on there way to meet Thors ship. Carter's not sure they have done the right thing, betraying and leaving Fifth, using his humanity against him, but O' Neill tells them they had no choice.

SG-1 returns from an off-world mission with an ancient artefact that triggers the ability to see hideous yet harmless life forms in a parallel reality. As the effect spreads to civilians off base, O'Neill and SG-1 must find a solution before mass hysteria breaks out.

Senator Kinsey suffers an assassination attempt while campaigning for the office of president, and O'Neill is caught on tape leaving the building where the shots were fired. With O'Neill behind bars, Carter, Teal'c and Jonas must prove his innocence before it's too late.

Colonel Maybourne visits O'Neill and claims to have a key to a cache of alien technology - but he demands a presidential pardon for his crimes in exchange for the knowledge. When SG-1 accompanies Maybourne to retrieve the cache, the find that his intentions may not be all they seem.

Jack and Maybourne soon find themselves on a barren planet, with all the habitants dead, and with no way to return. Can Sam figure out a way to bring them back?

SG-1 discovers that Nirrti, in an attempt to create the perfect human host, is mutating the inhabitants of an unexplored planet with a machine that rearranges their DNA. Captured in an attempt to stop her, O'Neill must find a way to escape before he and SG-1 are subjected to the same fate.

General Hammond, Major Davis along with the Russians, finally reveal details to the French, English and Chinese about the Stargate Project. However, things are made worse by Senator Kinsey who seizes the opportunity to try and get power of the Stargate Command.

By viewing clips from past shows, General Hammond tries to convince the three countries to keep it a secret and allow them to have control of the gate at the same time. However, Kinsey tries to get the control back into the hands of the NID. Kinsey has now, been elected, Head of a committee with control of the NID so if they get control he will ultimately be in control of it.

He nearly succeeds as the other countries threaten to tell their population about it, despite Russia backing the US. However, when things start to look bad, General Hammond calls Thor who asks that the control stay in the hands of the US Air force and with that, the other countries agree.

Whilst on a new planet, SG-1 discovers a crashed ship, and realise that they are not alone. Soon they meet the crew of the ship, 3 humanoids, who are being attacked by aliens, and without their ship, they can't get home. Jack agrees to help them, and in return wants to learn about the ship and technology.

The female member of the humonoid group, is injured in a shootout and returns with Jonas to Earth, whilst Sam and the leader of the group try to fix the ship. Meanwhilst, Jack is on the look out for the aliens that is attacking them. However, they have doubts as to the true intention of the crew and to who the true aggressors are. Their doubts are confirmed, when they capture the Alien, who tells them the truth, the humanoids are escaped convicts, and the ship was a prison transport vessel.

In the meantime, Jonas is getting suspicious of the female crew member, who is trying to extract information from him by flirting, and sets a trap for her.

Once Sam has got the the computer running she realises that it is in fact a prison transport vessel, and realises who the real enemies are. She is able to overpower one, of them however the third member of the crew is able to set him free, and knocks out Sam.

SG-1 with the help of the aliens try to take over the ship, however, Jonas is captured by the female, and is used as leverage to allow them to go through the gate unharmed. However, the gate address she has is that of Earth, and she falls into the trap set by Jonas. With all three of the prisoners captured, the Alien is able to complete his mission having made a new friend.

In a busy hospital Teal'c is being wheeled into surgery. As the surgeon in charge looks at him, the doctor's eyes glow white: It is the Goa'uld system lord Apophis.

Teal'c awakens startled, in his bunk at the fire house where fellow fire-fighter Jonas Quinn seems concerned. Teal'c does not have his head markings, and is speaking to Jonas in Earth slang, calling him "man" and "probie" — the nickname for new recruits, on probationary status. Teal'c says he's fine and to go back to sleep. But then Teal'c notices his symbiote pouch is missing. Teal'c awakens from his hibernation-like state of Kelnoreem to find himself back in his quarters at Stargate Command.

Later, in the SGC mess hall, Major Carter suggests that perhaps Teal'c is concerned about the upcoming mission. Teal'c suddenly finds himself back at the fire house with Captain Carter suggesting that perhaps he was worrying about his upcoming surgery, in which he would be donating a kidney to his stepfather, Brae. Fire Chief O'Neill suggests Teal'c give the matter more thought. But there is no better donor-match and he cannot let Brae die.

The alarm sounds and the fire-fighters are called to a highway accident. One of the men being carried out on a stretcher looks up at Teal'c — his eyes glowing white. Again, it is Apophis. Chief O'Neill orders everyone away from the site, as one of the cars is about to explode. But Teal'c sees Brae — whom he now knows is his father-figure, Bratac, in his other reality — trapped in the car—. . . which car explodes, its force throwing Teal'c clear but injuring him.

Teal'c now finds himself collapsed on the floor of the SGC cafeteria, and he's rushed to the infirmary. Dr. Fraiser is quite concerned: No Jaffa has ever fainted before.

In Teal'c's other reality at the hospital after the explosion, Brae/Bratac points out how strange it is that Teal'c was not burned or even scratched. Teal'c's wife Shauna, who was Shaun'auc in his other reality, is deeply concerned as well, and asks Chief O'Neill to get Teal'c some help.

The help comes in the form of Dr. Daniel Jackson — who tells Teal'c he's postponed the kidney transplant, but promises he'll do everything he can to help save Brae/Bratac.

Back at SGC, Teal'c goes through the Stargate, only to return to the hospital where Apophis keeps appearing, both as himself and as a surgeon. Apophis tells him, "You cannot escape your fate, shol'va," using the Jaffa word for "traitor."

Back at the hospital, Brae/Bratac begs Teal'c to let him die, but Teal'c refuses. Daniel Jackson appears again, and talks Teal'c through the similarities between his life as a fire-fighter and as a Jaffa working for the Tau'ri (Earth humans) against the Goa'uld. Both seem equally real. Then Daniel suggests the impossible — that neither scenario is real.

It finally occurs to Teal'c what has happened. Back at SGC with Dr. Frasier, O'Neill and the rest of SG-1, he recalls a meeting of the rebel leaders that had turned out to be a trap. Apophis' troops had slaughtered a hundred Jaffa and removed their symbiotes. Teal'c found Bratac, and passed his symbiote between them until help arrived.

But they had each gone without a symbiote for too long, and are both about to die. General Hammond contacts the Tok'ra, of whom Malek divines a solution. They adapt for Jaffa physiology the human life-extending drug tretonin — a distillate of Goa'uld symbiotes — that SG-1 had brought back from the planet of the Pangarans. If it works, it would mean that both Bratac and Teal'c will be able to live without their symbiotes — though they will be dependent on the drug until the Tok'ra can devise a way to make the effects permanent.

The experiment is a success. As Teal'c recovers in the infirmary, Daniel Jackson materializes from his ascended plane to assure him that Bratac is fine — and that this reality is indeed genuine. Teal'c sees this as a very good thing, because it means that his and Bratac's new ability to live without their symbiotes could one day mean the end of Goa'uld oppression for all Jaffa.

Colonel Jack O'Neill is miffed about being taken off SG missions to babysit the commander and crew of the Prometheus on her shakedown cruise. But both General Hammond and General Greer feel that SG-1 has valuable experience with both hyperspace travel and this interstellar spacecraft, having already saved it from the Goa'uld and used it to help the Asgard. As it happens, Flight Commander Colonel William Renson isn't too keen on SG-1's being there, either.

The ship comes out of hyperspace nine minutes ahead of schedule, the result of a hyperdrive problem. Major Samantha Carter explains that when the Naquadria energy levels rise too high, there is a buffer, like a surge protector, that is supposed to prevent instability. But the buffer is broken. Jonas Quinn checks the ship's sensor log and discovers that the Prometheus had passed through the intense gravity wave of an exploding star while in hyperspace.

Jonas notes that, according to the cartouche that lists all the planets with Stargates, the Prometheus was fairly close to P3X-744. So Colonel Renson okays using the hyperdrive for a quick burst theoretically too short for much chance of instability. Carter would use the planet's Stargate to 'Gate home, get the supplies she needs, and come back to repair the buffer so that the Prometheus can return home.

But when they get to P3X-744, the Naquadria reactor goes critical and has to be jettisoned. The resulting electromagnetic pulse damages the Prometheus further and is perceived by the people on the planet below as an attack. They launch missiles in retaliation. Renson orders the missiles shot down, but the ship's weapons control is off-line. O'Neill, on comlink, explains to their attackers that the EMP was an accident and asks them to please not destroy the ship. It works: The missiles self-destruct and the Prometheus is instructed to land by Commander Kalfas of the Tangean security force.

Renson and SG-1 meet with Tangean Chairperson Ashwan, who is happy to meet visitors from another world and offers to help SG-1 find the Stargate, which they call the "Ring of the Gods." To them it is just a myth, but they let Jonas, Teal'c, and Carter go through the Tangean history books to research its whereabouts.

Kalfas is not happy about this. He is in political competition with Ashwan, who is increasingly being perceived as weak in matters of civic defence. And the arrival of the Prometheus did not help matters much.

Tangean history, however, only goes back 300 years; the "dark age" before that was erased from the record. But Jonas and Teal'c meet a Tangean historian who had found some Goa'uld artefacts that led him to believe Horus was his god. According to Teal'c, Horus was Heru-ur—a Goa'uld system lord who'd invaded the Asgard home world of Cimmeria and tried to kidnap the son of his rival, Apophis. It appears Heru-ur had brought the Tangeans from Earth centuries ago, enslaved them, and, after depleting the planet's riches, departed.

Among the artefacts is a map leading to where the Stargate is buried. With Ashwan's assistance, SG-1 unearths the 'Gate and gets it up and running. Then Kalfas and his army unexpectedly arrive to take over.

SG-1 needs the Prometheus to overpower Kalfas, but the Tangean has guns aimed at it. Ashwan assures Renson and SG-1 that Prometheus will not be fired upon. Colonel Renson is sceptical until Ashwan boards and puts himself at risk.

Ashwan emerges from Prometheus and makes an eloquent speech to Kalfas' armies about how the 'Gate is the key to the Tangeans' past and future. He successfully orders the soldiers to lower their weapons and take Kalfas away. Carter can now return to SGC and get the parts needed so that the Prometheus can return home.

SG-1 is on planet P4S-237, talking to the people there who have been oppressed by the Goa'uld system lord Ba'al, whose emissary Lord Mot comes to the planet regularly to collect a tribute in the form of Naquadah.

The people's elder, Ellori, says a prophecy foretells strangers coming through the Stargate and freeing them from Ba'al's tyranny. It made sense that SG-1 are those strangers. Just then, Jonas Quinn sees and hears Ellori's young advisor, Chazen, say, "Stop talking like a fool. It would be madness to defy Lord Mot." No one else hears it until a few moments later—when Chazen actually says it.

Jonas falls unconscious and is rushed to Stargate Command's infirmary, where Dr. Janet Fraiser finds nothing physically wrong with him—though his MRI does show an area of unusual brain activity. She recalls how Jonas' fellow scientists on his off world homeland of Kelowna suffered from headaches and later schizophrenia from excessive exposure to the Naquadah derivative Naquadria.

Jonas experiences another premonition during a briefing in which SG-1 determines Ba'al hasn't been to P4S-237 for generations because he thought the Naquadah mines had dried up. Mot was hoarding the Naquadah for himself so that he could move against Ba'al. Then Jonas sees and hears Major Carter ask him if he wants Mexican food for lunch—which she doesn't actually do until she comes into his office after the briefing.

Jonas now realizes that he is seeing and hearing the future. The rest doubt him—until he tells SG-1 that a Tok'ra named Sina is arriving through the 'Gate and, moments later, she does so. Sina tells SGC that Lord Ba'al is in trouble with Anubis for allowing the defiant system lord Yu to escape. With Ba'al in Anubis' bad graces, Mot is now in a prime position to replace Ba'al and claim P4S-237 for himself.

Dr. Fraiser discovers a rapidly growing tumour in Jonas' brain. If she doesn't remove it soon, Jonas will die.

This tumour, Carter and Jonas surmise, was not due to Naquadria overexposure but to the long time Jonas had spent in the Goa'uld Nirrti's gene-splicing device ("Metamorphosis"). Her experiments gave him the gift of foresight—but with a fatal price.

Dr. Fraiser wants to operate immediately. But Jonas hopes the tumour will stabilize so he can control it and predict Goa'uld attacks. General Hammond grudgingly gives Jonas 24 hours, under Dr. Fraiser's observation, to come up with some valuable precognizant intel, while Carter, Teal'c, and Colonel O'Neill prepare to return to P4S-237.

Suddenly, Jonas has a vision of Major Carter being wheeled out of the 'Gate room in cardiac arrest. He immediately runs down there to stop the mission. General Hammond decides to err on the side of caution and has Major Carter sit the mission out. Teal'c and Colonel O'Neill go on ahead with SG-15. But later, Major Carter goes into cardiac arrest after an electrical accident at SGC. Had she gone on the mission, she wouldn't have been hurt.

Carter pulls through. Jonas is still intent on trying to control the visions and uses Teal'c's Kelnoreem technique as an aid. He then has a vision of Teal'c and Colonel O'Neill being ambushed at the Stargate on P4S-237 and of the iris on the SGC Stargate opening and an army of Jaffa coming through. He then collapses. Dr. Fraiser immediately wheels him into surgery to remove the tumour. But Jonas manages to tell Carter about the vision, and she warns General Hammond.

While Jonas is in surgery, General Hammond, unable to contact SG-1 or SG-15, has the 'Gate room loaded with armed guards in case the vision comes true. Just then, Colonel O'Neill, Teal'c, and SG-15 come through with some wounded. They had been helped by the people of P4S-237 to overtake Mot and his Jaffa who were, as Jonas saw, intending to ambush them.

Daniel Jackson appears to O'Neill and alerts him that Anubis has located the Eye of Ra, a fabled object of power, hidden somewhere on Abydos, and he must find it before Anubis and save Abydos. With the help of Daniel, O'Neill and SG-1 find the Eye first however, they are pin-downed by Anubis's Jaffa, and have no way out. Determined to have it, Anubis threatens to destroy the entire planet unless Daniel and SG-1 hand it over, and whilst Jack thinks its not a good idea to trust Anubis or any Goa'uld, Daniel thinks that it may be the only way to save the people of Abydos.