Unlike Stargate: The Ark of Truth, which acted as the "true" series finale, Continuum is a standalone story. As SG-1 and General O'Neill attend the execution of the System Lord Ba'al (or so they think), the real Ba'al goes back in time to destroy Earth's Stargate as it is transported by sea to the United States — coincidentally by Cameron Mitchell's Identical Grandfather. While the Stargate is saved, everyone aboard the ship is killed, resulting in it being stranded in the Arctic and the Stargate lost. As the Tok'ra city vanishes around them, SG-1 rush for the Stargate to find a different Earth — one where the Stargate program was never launched and Earth is now defenseless against Ba'al, who used his knowledge from time travel to defeat the other System Lords.
This film provides examples of the following tropes:
- Actually Pretty Funny: Ba'al to Apophis:Apophis: May your reign last days, and your death years!
Ba'al: (chuckling, glances at Teal'c) That's actually rather good, isn't it?
- Affably Evil: Where the other System Lords rule through terror, demand absolute worship, brutally suppress any rebellion, and betray everybody at every opportunity, Ba'al respects his subjects and minions, keeps his promises, and wishes to conquer Earth peacefully and for mutual benefit. It's not so much that he has a greater respect for life than his contemporaries, so much as that he's realized how stupid and counterproductive the old way of doing things was. His inability to get back into the paranoid, spiteful mindset of a System Lord might explain how Qetesh's betrayal caught him by surprise.
- Alas, Poor Villain: Ba'al genuinely wants to rule Earth with benevolence, which actually sounds awesome for us. Unfortunately, he swiftly gets betrayed by Qetesh, who then sets about performing the more traditional Goa'uld invasion... which is somewhat less awesome.
- America Saves the Day: Subverted. The American heroes need help from the Russians to reverse the Goa'uld invasion of Earth. President Henry Hayes also notes to Ba'al that the U.S. is just one of many sovereign nations when the latter essentially treats him as humanity's representative.
- As Himself: The entire crew of the USS Alexandria.
- Awesomeness by Analysis: Rather than invent time travel, Ba'al uses the tried-and-true method of time travel by solar flare/wormhole and scales it up by setting up satellites at thousands of stars to monitor for solar activity, networked with a supercomputer that will calculate their exact effects on the wormhole. This way, all he has to do it wait for a star to oblige him with a flare that is within his specifications and dial the appropriate address.
- Badass Bystander: The Achilles crewman who checks out the hold of the ship for damage comes across the active Stargate just as Ba'al and his Jaffa are coming through. He immediately helps Mitchell kill them off with a Thompson submachine gun, no questions asked.
- Bait-and-Switch: There's a bit during Baal's introduction as the newly self-appointed emperor of the entire Goa'uld Domain where he shouts "Bring in the prisoner!", succeeded by the camera following Teal'c walking into the throne room and positioned in a way that implies Teal'c has been captured by Baal's forces. Die-hard fans of the shows should already notice things are up because Teal'c actually has Baal's golden sigil engraved on his forehead, not that of his former master Apophis. Indeed, Apophis is the real prisoner, who has been captured by Teal'c after he defected to Baal.
- Benevolent Alien Invasion: Ba'al genuinely intends to do this, where in exchange for acknowledging him as Supreme Leader, he'll let Earth remain as a self-autonomous protectorate in his dominion, even allowing them access to Goa'uld technology as a show of good faith and mutual co-operation. The other System Lords clearly think he's gone insane.
- BFG: Vala tries to take one to the execution... ahem... extraction of Ba'al from his host, just in case. A bit of a Continuity Nod as the gun was the X-699 from the SG-1 episode "Bounty". Production-wise, the gun was meant to help conceal that Claudia Black was pregnant. This is also why Vala/Qetesh wears a loose gown later in the film.
- Bond One-Liner: Ba'al drops one when he kills Apophis.Ba'al: That's actually rather good, isn't it? (draws his sword)
Did you plan to say that when you walked in? (slices off the top of Apophis' head)
Or was it just off the top of your head?
- Boom, Headshot!: How Mitchell finally kills Ba'al. The response on Ba'al's face just before he dies is priceless.
- Conqueror from the Future: Ba'al uses a time travel device to reverse the fallen fortunes of the Goa'uld empire and take the galactic throne for himself. He prevents the SGC from ever coming into existence so Earth will be defenseless when the Goa'uld fleet finally comes and then eliminates all the rival factions one by one before invading Earth.
- Consummate Liar: Lampshaded. Ba'al's clone is about to be executed by the Tok'ra, and during his last words he gloats to SG-1 about the plan his originator has set in motion to undo everything they have done. Because he's known for being a liar, they're not convinced and think he's just stalling for time, but it turns out that he was telling the truth after all.Teal'c: He lies.
O'Neill: He does that, you know.
- Dead Alternate Counterpart: When SG-1 travels back to Earth and arrive in a timeline that has been altered by one of their enemies, this turns out to be the case with some of them. Carter's counterpart (an astronaut) was killed by performing a Heroic Sacrifice during a space mission, while Mitchell's counterpart never even existed because his grandfather was killed by the villain during his visit, thus making him a literal example of a Grandfather Paradox. Jackson's counterpart is still alive, but is living on the fringe of society as a crackpot scientist because his Ancient Astronauts hypothesis never got any recognition.
- Delayed Ripple Effect: The effects of Ba'al's time travel work like this. Possibly justifed in-universe as having the people who were affected earlier in the revised timeline (such as Vala/Qetesh) vanishing first.
- Dying Curse: Apophis gets a damn good one. Ba'al even compliments him on it.Apophis: May your reign last days, and your death years.
- Emergency Refuelling: The heroes refuel their plane before trying to head to the other Stargate in an attempt to Set Right What Once Went Wrong. However, shortly after they refuel, the tanker gets taken out by an Orbital Bombardment. Later, Mitchell complains about getting shorted in the fuel tank by the last tanker.
- Eviler Than Thou: The other Goa'uld System Lords are appalled at Ba'al's choice of a pragmatic strategy for the invasion of Earth by framing it as the start of a benevolent new alliance for the Tau'ri/humans. His consort Qetesh assassinates him for this and orders the fleet to get back to their traditional way of doing things: blast the humans down to more "manageable" numbers with an orbital bombardment.
- Evil Will Fail: The Goa'uld, under Ba'al, have become an unbeatable force. However, the treacherous nature of the Goa'uld rears its head, and Ba'al is literally stabbed in the back, which ultimately leads to the end of the Goa'uld empire.
- Final Solution: The Goa'uld consider the human population of Earth to have grown beyond their control. After Qetesh takes over from Ba'al, they decide to remedy this by orbitally bombarding the planet and reducing it to a more "manageable" number by killing as many people as possible.
- Foreshadowing: Apophis never knew how prophetic his wish was that his enemy Ba'al's reign "last days and his death years". In fact, Ba'al dies within less than a day from the moment he kills Apophis.
- For Want of a Nail: Ba'al causes this intentionally, with plenty of resulting changes. The Stargate was lost when the ship carrying it across the ocean to America was lost with all hands on board. One effect of one of those people dying was made explicit. The captain was Mitchell's Identical Grandfather, and he hadn't had kids yet. Unusually, some of it was quite positive—for instance, Jack O'Neill's son, dead in the original timeline, was doing just fine. The interesting thing here is that Jack's son died in a tragic accident which bore no relation to the Stargate program at all. So the butterfly effect must have been at work in really subtle and far-reaching ways...
- Godzilla Threshold: Once the Goa'uld destroy McMurdo Base and the Antarctic weapons platform, President Hayes authorizes SG-1 to head for the Russian Stargate and hopefully alter the timeline back.
- Gondor Calls for Aid: The Russians show up just as a squadron of Gliders are about to vaporize our heroes.
- Grandfather Paradox: Inverted, where Cam Mitchell winds up going back in time, and eventually (ten years down the road) keeping his Grandfather alive as a way of setting right what Ba'al had messed up. Said paradox is directly referenced before, when Mitchell finds out that he doesn't exist in new timeline because Ba'al killed his grandfather.
- Grand Finale: Stargate: The Ark of Truth resolved the Ori arc, Continuum resolves the Ba'al arc.
- Half the Man He Used to Be: Qetesh uses an enhanced blade to cut Ba'al cleanly in half from the waist up.
- Heroic BSoD: When the Ba'al clone stabs O'Neill during the extraction ceremony, killing him, Carter is so distraught that Cam has to yell at her and then actually grab her vest and pull her up to get her to leave Jack's body and go through the Stargate with him and Daniel. Once they're on the other side of the gate, she's still so stunned that she just stands there for a minute, not speaking or moving.
- Heroic Sacrifice:
- SG-1 certifies and laminates their Badass Crew card when the four of them get wasted one-by-one holding off Qetesh's Jaffa hordes.
- SG-1's fighter escorts engage a large force of Death Gliders to buy them time to reach the Russian Stargate. They're not explicitly shown being shot down, but the odds definitely weren't in their favor.
- Hide Your Pregnancy: Claudia Black was pregnant while filming, so they filmed her character in loose dresses, from certain angles, and holding a BFG, to hide it.
- Hoist by His Own Petard: Ba'al is ultimately defeated by his own genre savviness, then for added insult SG-1 turns his own time machine against him, foiling his plot before it technically even started.
- Hostage Situation: When Teal'c walks in on Qetesh having stabbed Ba'al through the torso, she threatens to kill him if Teal'c comes closer. Teal'c defaults to avenging Ba'al's death despite his protests, having accurately deduced that Qetesh was going to kill him no matter what. Which she does.
- Identical Grandson: And his grandfather's identical best friend in Cam's locker room picture.
- I Die Free: Teal'c says the Rebel Jaffa's signature line just before he blows up Qetesh and himself.
- Instant Death Bullet: Averted. Despite receiving a bullet right to his forehead courtesy of Cam, Ba'al's Goa'uld resilience means that it still takes a couple of seconds before he's dead, leaving him just enough time to wonder what the hell went wrong with his plan.
- Interservice Rivalry: Carter and Mitchell, both Air Force officers, give each other a look when they find out that the Navy will be running the alternate Stargate Program.
- I Was Told There Would Be Cake:O'Neill: That was the plan, right? Get rid of the last of the bad guys and then... cake.
- Killed Off for Real: After dozens of Ba'al's clones have been killed throughout the last few seasons of the series and he has continually escaped death to return yet again, both the last clone and the original Ba'al are finally killed for good by SG-1.
- Kneel Before Zod: Defied. Ba'al simply calls up the U.S. President to have a relatively civil discussion with him about an Earth-Go'uld alliance, instead of beaming directly into the Oval Office to demand the unconditional subjugation of mankind. Ba'al recognizes that the usual Goa'uld tactic is too melodramatic and ineffective.
- List of Transgressions: SG-1 is asked to be present at the execution of (probably) the last Ba'al clone. Apparently the Tok'ra felt the need to list ALL of his crimes.Daniel: (three hours into the ceremony) I think we're getting to the end.
O'Neill: How can you tell?
Daniel: Well, the crimes they're listing are starting to sound familiar.
- Love Makes You Dumb: The otherwise clever Ba'al is so enamored with Qetesh and wants her to become his queen that he fails to consider that she's just another ambitious Goa'uld who would kill him to usurp his position at the first opportunity. Ba'al ends up getting a sword through the back.
- MookFace Turn: Teal'c again; counting "Moebius", this makes it the third timeline in which he sided with SG-1. Stargate SG-1 seemed to make a point that any timeline that didn't result in the Goa'uld conquering Earth HAD to include a defecting Teal'c. No Teal'c defection, no Earth victory. It was averted with respect to Teal'c and Ba'al. Teal'c never betrayed Ba'al, and sided with SG-1 to avenge his lord's murder. It was played straight with his presumed betrayal of Apophis.
- Nobody Poops: Because SG-1 flies across half the world in fighter jets without stopping. It's never said if they were intending on flying all the way to Antarctica in those jets, but they get diverted to Russia in the end. Partially Truth in Television, at least: there are bags and/or tubes for dealing with liquid waste on long flights. As for solid waste, well, there might be a reason g-suits are called "poopy suits"...
- Oh, Crap!: Ba'al gets a fairly spectacular one at the end when he steps through the Stargate and sees his dead Jaffa and Mitchell pointing a gun at him.
- The Oner: The movie starts with one taking us through Stargate Command.
- Orbital Bombardment: After killing Ba'al, Qetesh orders the Goa'uld fleet to open fire on Earth to reduce its population to a more manageable number.
- Peggy Sue: The plot executed by Ba'al is a subversion of the usual Mental Time Travel. As Ba'al ages very slowly he's able to step into his younger self's shoes and kill the spare.
- He may have torn his younger parasite out of the younger host body and transferred his Goa'uld self over...
- ... but he probably just executed both and kept his older human body intact or had a fresh clone made.
- Precision F-Strike
- When apparently left to freeze with a frostbitten leg in the middle of the Arctic, Dr. Daniel Jackson can say only one thing: "Oh, shit."
- Later, when Jackson is being interviewed he asks his interviewer "Who would make this shit up?"
- Reasonable Authority Figure: President Henry Hayes again cements himself as one. Even when he gave the order not to let SG-1 try and change the timeline back he's got well-thought out reasons for doing so.
- Red Herring: Major Davis can be seen walking into Stargate Command during the opening sequence. Considering he was normally the bearer of bad news on the show, you'd expect him to have a major part in the plot to follow. Nope. He's just a walk-on.
- Ret Gone: Cameron Mitchell didn't exist in the altered timeline because the man Ba'al killed to stop the Stargate from reaching North America was his grandfather. The other two teammates who retained their memory of the original history did have duplicates running around, though. One of them died in an unrelated incident by Heroic Sacrifice before the three of them showed up, and the other briefly talks to his clone over the phone.
- Ripple Effect-Proof Memory: For some reason, all of SG-1 are physically Ripple Effect Proof even when the world crumbles around them. Hand waved away by being "outside of our normal-space time in the wormhole when the timeline deteriorated." Though they presumably weren't outside of space time while they were running for the gate with time rippling and removing buildings and people around them.
However one can infer that since Ba'al had yet to invade Earth in the alternate-timeline and the Stargate was lost, then only their memories of the last ten years would have been altered when reality changed. In comparison, Vala still being host to Qetesh, Teal'c still serving as First Prime and the Tok'ra being destroyed were major changes, hence why they were the first to be affected.
- San Dimas Time: Apparently, Ba'al's meddling with the Stargate occurs "simultaneously" with the execution.
- Set Right What Once Went Wrong: The plot centers around the main cast being the only people to know that the timeline has been changed and trying to convince others to let them change things back. The trope is notably deconstructed when SG-1 gets a What the Hell, Hero? speech upon suggesting time travel; the issue is raised that this trope requires an Omniscient Morality License to work and that to assume you can go around Setting Right What Once Went Wrong is an act of staggering arrogance as it necessitates changing the lives of millions... of course it always goes From Bad to Worse and they're allowed to do it in the end.
- "Shaggy Dog" Story: The movie is one of these from Ba'al's point of view. After the fall of the Goa'uld in the normal timeline he has learned from their mistakes as a species. He goes back in time and spends decades uniting the normally feuding Goa'uld into the most powerful empire seen in the franchise's history. Then Goa'uld Chronic Backstabbing Disorder comes into play and everything falls apart.
- Sharpened to a Single Atom: The blade held by Ba'al (and later Qetesh) is "only one atom thick", thin enough to cut Ba'al clean in half.
- The Slow Path: Ba'al and Cam both arrive years before the main continuity. Cam presumably does not survive the wait.
- Cam also has to wait out a whole ten years to kill Ba'al because of the treachery of Qetesh interrupting the favorable time travel window.
- The Starscream: Qetesh murders Ba'al to learn his secrets, usurp his throne and turn the Goa'uld's policy back to genocide and mass slavery for the hell of it.
- Taking You with Me: Teal'c deals with Qetesh at the end by blowing her and the time travel device he was defending up alongside him.
- Talking to Themself: At one point, Daniel Jackson contacts his alternate timeline self on the phone to tell him he knows the book he wrote—about how the pyramids were much older than believed is true. Alternate Daniel hangs up on him.
- That Liar Lies: After the Ba'al clone gloats about the plan which the original Ba'al has set in motion, Teal'c looks him in the eye and calmly states "He lies". O'Neill's response: "He does that, you know".
- The Time Traveller's Dilemma: Explicitly referenced, and this is why SG-1 isn't allowed to revert the timeline — but obviously, they do it anyway. Of course since they've proved they live in a multi-verse where every possible thing that can happen will happen, it's strange that no-one ever seems to suggest moving via Quantum Mirror as a solution.
- Throw the Dog a Bone: The Russian Air Force finally gets to pull SG-1's asses out of the fire instead of the other way around when MiG-29s perform the final Gunship Rescue of the series.
- Timey-Wimey Ball: Basically, the only answer to the question "Why does time travel work this way in this movie?" is "Because." It's a nice Continuity Nod, however — Ba'al's Time Machine itself makes perfect sense within the show's continuity, as it uses long-established rules about how Stargates work, and doesn't really require any Applied Phlebotinum that hasn't already been seen in the series.
- Trust Password: Subverted twice:
- O'Neill refuses to buy it, partly because what Daniel tries to use as proof happened very differently in the alternate timeline.
- Landry believes Mitchell even without the recitation. He has, however, presumably been shown several days worth of interviews of each of them where they've been trying to slam the Trust Password into the face of everyone they come into contact with.
- You Are Not Alone: Daniel attempts to phone his counterpart, long-since discredited for his theories, telling him he was right and not to give up. Unfortunately, his counterpart believes he's being mocked and hangs up.