Stargate Continuum is the second direct-to-DVD film based on Stargate SG-1 and the third movie in the Stargate Verse overall.Unlike 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 Earthis 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:
Apophis: May your reign last days, and your death years! Baal:(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 get betrayed by Qetesh, who then sets about performing the more traditional Goa'uld invasion... which is somewhat less awesome.
Awesome yet Practical: So you've discovered that a Stargate wormhole which is routed through a certain type of solar flare (a real freak occurrence) becomes something of an accidental time machine. Suppose you want to build a purposeful time machine? Build some kind of freaky Star Trek machine that recreates the conditions of a solar flare by inverting the polariton variant? Nah. Build a giant astronomy network and watch for one of the galaxy's 100-billion-some-odd stars to oblige.
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.
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.
Dangerously Genre Savvy: Ba'al. He really should have seen the betrayal coming. Although one could argue on Ba'al's defense that he had actually been infatuated with Qetesh'shost Vala to the point where he might have forgotten or overlooked just how much of a liability Qetesh really was. Also possible as mentioned above that so long working around humans and building his new and improved empire of fluffy happy domination had dulled his instincts about just how insanely cutthroat the other System Lords normally would be.
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 be measured in hours, and your death in years.
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: obliterate every human on the planet with an orbital bombardment.
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.
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.
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.
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.
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.
List of Transgressions: SG-1 is asked to be present at the execution of the last (probably) 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.
Mook-Face 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.
Nice Job Fixing It, Villain: By backstabbing Ba'al, Qetesh sets off a chain of events that leads to the failure of Ba'al's last-ditch plan to rewrite history and reverse the fallen fortunes of the Goa'uld Empire.
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"...
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.
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?"
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.
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.
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: Cam has to wait a few years near the end of the movie.
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.
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 as a solution.
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.
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.