A teenager claiming to be Colonel Jack O'Neill arrives in Stargate Command. At first believed to be an imposter, the teen manages to recite key facts about his fellow team members. After believing it to be O'Neill, they find out he's a botched clone. They investigate what's happened to the real O'Neill and discover that a rogue Asgard may be responsible.
Carter and Hammond meet the "intruder".
Major Samantha Carter arrives at Stargate Command and meets up with Major General George S. Hammond. where she is informed of an intruder on the base. Hammond tells her that the intruder has used Colonel Jack O'Neill 's ID card to enter the base. When they walk to the holding room the intruder is being held, Carter is surprised to learn that the intruder is a 15 year old boy wearing clothes that are obviously too big for him. The boy claims that despite appearances, he is Jack O'Neill.
The boy tells Carter that last night, he had dinner and a beer. and then went to sleep, and woke up like he is now. No one believes his claim. Soon, Dr. Daniel Jackson and Teal'c arrive to see the "intruder," but they also do not believe him. The boy then recites major events from the team's past, including Carter being taken as a host by Jolinar of Malkshur. Daniel's ascension. and that Teal'c has been taking Tretonin since he lost his symbiote. After the team leaves, Hammond wonders how the boy could have access to such classified information. Carter starts to think that the boy may be O'Neill. The only way to know for sure is to run tests on him.
Some time later, Hammond and SG-1. except O'Neill, are in the Briefing room with Dr. Janet Fraiser. who ran DNA tests on the boy and compared them to O'Neill's sample. It is almost a complete match, with a tiny margin of error, tiny enough to convince them that the boy is in fact O'Neill. Fraiser also finds a tiny abnormality, but has no idea what it might be. Carter and Teal'c later see young O'Neill, and attempt to encourage him to enjoy his new found youth while he can, until a solution can be found.
The team investigate O'Neill's home.
Later, the team arrives at O'Neill's house to investigate what might have caused his youth. They find some food, which they plan on taking back to the SGC for analysis. While doing some more investigating, O'Neill receives a short flashback with floating lights, and an alien head peering down on him. He tells the team his flashback; he believes that last night, he may have been visited by an Asgard.
Back in Stargate Command, the team reports to Hammond about the findings. Hammond is skeptical, but he allows Jackson and Teal'c to investigate past alien abductions with accounts similar to O'Neill's flashback. Meanwhile, Carter is to give out a presentation on how to fly F-302 fighter-interceptors to a group of pilots, even though it was originally O'Neill who was to give out the presentation, until circumstances changed. Jackson and Teal'c manage to narrow the database for all alien abduction accounts that match O'Neill's description, and they find eight known claims in the United States of America alone, with them going on for the past 19 years, so they decide to visit the eight people.
Carter finds O'Neill in some trouble with two SFs.
Carter is giving a group of pilots a presentation on 302s, and gives them a packet for Operation Blue Phoenix to test the flight capabilities of the 302s. The pilots seem more eager to listen to O'Neill, though she tells them that he is unavailable. The briefing is cut short by some commotion from outside, between O'Neill and an SF. Carter lets O'Neill in, and explains that this is O'Neill. Though the pilots at first refuse to listen, the boy convinces them otherwise, and successfully gets the pilots' attention.
Jackson and Teal'c talk to the eight people who claimed they were abducted by Aliens (presumably the same Asgard from O'Neill's flashback), where the eight give away exactly the same description from O'Neill's experience; however, none of them experienced any physical changes, such as being their younger selves. Carter attempts to contact the Asgard, but doesn't hear anything yet. However, Dr. Fraiser warns the team that help better arrive soon, because she learns that although he may not feel any side-effects yet, he's dying.
Fraiser explains to O'Neill that his degeneration may take days or weeks. The side effects will include fatigue and the shut down of vital internal organs. With the Asgard not coming, they seek help from the Tok'ra. who send Selmak /Jacob Carter to Earth. They give him a solution: instead of implanting him with a Tok'ra symbiote like last time. they could send him in a stasis pod until they can find a way to halt his cellular degeneration. A reluctant O'Neill asks for five minutes to think about it. Hammond gives him ten minutes. While the rest of the team wonders if he will do it, they detect a security breach. Young O'Neill is actually behind this, and since he knows the SGC plans very well, he quickly manages to escape Stargate Command. Hammond calls the local authorities to search for him.
Soon, O'Neill attempts to buy beer from a store, but is quickly kicked out for being too young. He then spots Lt. Colonel Harlan Beck. who used to serve with O'Neill during Operation Prove Force in the Gulf War. Young O'Neill tells Harlan that he is O'Neill's nephew, and wants him to buy some beer for the boy, though Harlan refuses to do so. In the SGC, Fraiser and Selmak discover what the small abnormality from his DNA's test might be; the young O'Neill is a clone.
The team finds O'Neill.
Jackson thinks he knows why he's a clone (being aware of the Asgard's 'degeneration' problem): the Asgard must have cloned the abducted to not arouse any suspicion, so the Asgard could do tests on the abducted, until he is finished, and then switch the bodies back again. In that case, the real O'Neill would return again soon, but in order for the plan to succeed, they need to recapture "Duplicate O'Neill". They then get a phone call from Harlan Beck, concerning O'Neill's "nephew". With that information, they are able to find Duplicate O'Neill in a wooded area by a stream, where they tell him that he's been cloned by an Asgard, and he doesn't have to go into stasis. Instead, they can work on a plan to apprehend the Asgard responsible. O'Neill ultimately agrees to this (though he's not impressed with their apparent disregard for his predicament, just as long as they can get the 'original' O'Neill back), and they plan to send him back to his cabin, where the Asgard would beam the original O'Neill back and take Duplicate O'Neill; he hopes
to stop the Asgard, and beam the others on board. Hammond agrees to give O'Neill a Zat'nik'tel. when he insists he's the only one who can do it.
The culprit for the clone is revealed.
That night, Duplicate O'Neill is on his bed, with his team outside the house, when suddenly he is beamed away by an Asgard transporter. The rest of the team rush to his house, where they see the original O'Neill, lying in bed, waking up, wondering what the rest of his team is doing in his bedroom. Meanwhile, Duplicate O'Neill is on board an Asgard science vessel. where an Asgard tells him not to be afraid. However, he is then stunned by O'Neill's Zat. Duplicate O'Neill goes down and finds a console, where he manages to beam the rest of his team on board.
The team informs the real O'Neill that he has been abducted by an Asgard for seven days, and that for that time, a clone of him has been made. The Asgard wakes up, and tells the team that his name is Loki. the Norse god of Mischief. Loki tells them that he is a scientist, and for two decades has been abducting humans to conduct research on them. Since the Asgard's cells are degenerating due to excessive cloning, the Asgard will soon die out, and experimenting on humans may hold the solution; he discovered about O'Neill's reputation, as he is "legendary" among the Asgard. As a result Loki wondered if he may hold the key to end the Asgard cloning problem. He made clones so as not to arouse the suspicion of the public, but made them in a way that they would not live for long, though even Loki doesn't know why the clone has not reached the target age of 51.
O'Neill decides to have Carter contact Thor. against Loki's wishes. After a few seconds, Thor manages to beam himself on board. Duplicate O'Neill starts to feel the effects of his degeneration. Thor explains that O'Neill's unique DNA has been altered by the Asgard to provide tamper-evident safeties against illicit research like that conducted by Loki, which resulted in the premature state of O'Neill's clone. He assures them that Loki will be punished for his crimes, and after some convincing from O'Neill, Thor agrees to repair the clone's DNA, so he will no longer feel the effects of degeneration - thus, saving his life.
O'Neill drops his clone off at High School.
Some time later, O'Neill drops his clone off outside Mountain Springs High School. so the duplicate can have a chance to embrace it, something the real O'Neill never did. He's relishing the idea of starting all over again, with all the extra knowledge he's gained - something most people wish but never have the chance to do. He asks O'Neill if he doesn't wish to do the same if he could, to which O'Neill says it has never crossed his mind. The clone then agrees not to keep in contact, since both agree that would be "weird," and not to worry as the United States Air Force would take care of anything he might need. In the end, O'Neill wonders if his younger self is sure about this, which he ensures he is (when O'Neill notices some nearby girls giving him the eye, he's all the more understanding why the young O'Neill is willing to put himself through this.) O'Neill wishes him well on his way, so his younger self can start High School, as well as hang out with the three girls flirting with him. The Colonel the drives off with a knowing smile on his face.
Jackson. Okay, love to, who are you?
Hammond. Are you saying Colonel O'Neill has somehow regressed more than 30 years overnight?
Jackson. Stranger things have happened.
Teal'c. Name but one.
Jackson. Well, there was the time he got really old, the time he became a caveman, the time we all swapped bodies.
Hammond. In the mean time I suggest we make him as comfortable as possible.
Carter. I'll go set up a PlayStation.
Young O'Neill. You know, I think you two are enjoying this just. a little too much.
Carter. Well, you are kinda cute.
Young O'Neill. That's "Sir" to you. And being trapped inside a scrawny little body isn't my idea of cute, Carter.
Teal'c. Does possessing a younger body not have certain advantages, O'Neill?
Young O'Neill. No. Not seein' it. What do you mean?
Teal'c. Do you not experience increased health and vitality?
Young O'Neill. My "vitality" was just fine, thank you.
(Before the F-302 briefing, Jack speaks to Hammond in his office about his situation because he got stripped off the briefing.)
Hammond. Come in. Jack, try to understand. Your situation puts me in a very difficult position.
Young O'Neill. General, no offense, but you're not the one who went to bed watching CNN and woke up as part of the MTV generation.
(While Carter gives a presentation on F-302s, she hears commotion between O'Neill and an SF outside the room)
Young O'Neill. I just dropped by to say. Ow!
SF. Sir, please do not resist.
Young O'Neill. Hey, ease up, big guy.
SF. Relax, sir.
Young O'Neill. I'm warning you.
SF. Sir, please, stay there.
Young O'Neill. Did I just say I'm warning you? Hey! Oh! All right! That's it! Now, I'm mad!
Jackson. Look, we're not here to take you to the Tok'ra. There may not be much time.
Young O'Neill. Never is, is there.
Jackson. Okay, well, (sighs ) there's no easy way to tell you this so. Sam's just gonna come right out and say it. (Carter looks at him )
O'Neill. What's goin' on?
Jackson. We're pretty sure this Ass-gard kidnapped you and attempted to replace you with a clone.
O'Neill. How long was I asleep?
Carter. Seven days.
O'Neill. That's a record.
Loki. What's happening?
Carter. We were kind of hoping you could tell us.
Loki. No, no, no, this is all wrong.
O'Neill. Hey. I'll tell you what's wrong. I just woke up, haven't had coffee, let alone a pee in seven days, and I find out you stole my ass and made a mini-me! Carter, I should be irked, currently, yes?
Carter. Yes, I-I would be.
Young O'Neill. Maybe you're a little put out, but this guy didn't hit all the right buttons on the Xerox. This body is gonna fall apart if he doesn't fix me.
O'Neill. You sure about this. I mean. it's High School. (Young O'Neill looks back at the three girls looking at him, then turns back ) Yes. Go forth young man.