"You should know that I've placed a naquadah bomb somewhere in the United States. Consider it a precautionary measure. If another attempt is made to capture me, I promise you the consequences will be most dire."
— Ba'al
When a Jaffa is mysteriously found dead on a Virginia road, the team discover that Gerak has secretly been sending his forces to Earth in order to search for Ba'al, who is revealed to have gone into hiding there following the destruction of his fleet. Ba'al contacts the SGC and threatens to detonate a naquadah bomb somewhere in the US if they don't call off the search.
"Ex Deus Machina" provides examples of the following tropes:
- Aliens in Cardiff: A fully-armored platoon of Jaffa in a US office building.
- Big, Bulky Bomb: Ba'al tells SGC that he's placed a bomb in a new building in Seattle. When the bomb disposal team finds naquadah throughout the building's superstructure, Carter figures out that the whole building is the bomb.
- Body Double: Subverted. Ba'al is spotted at a hotel and a mission to capture him is launched, only to be aborted when Ba'al holds a televised press conference across town. Figuring that the other one is a fake, they let him go. Eventually, the heroes discover that Ba'al acquired cloning technology. He really was in multiple places at once.
- Cassandra Truth: Carter's evidence that Ba'al has cloned himself and that the Ba'al Gerak captured and executed wasn't the real McCoy. Teal'c even cites this Trope and knows the Jaffa won't listen to it (or believe him).
- Cold-Blooded Torture: Gerak has the Goa'ulded Alex Jameson tortured for information.
- Continuity Nod:
- Several references are made to the events of "Endgame", and the symbiote poison is used again.
- Carter tells Barrett that she's broken up with Pete.
- Dogged Nice Guy: Agent Barrett, towards Carter.
- Exact Words: Teal'c stresses that though he's promised to deliver Ba'al to Gerak, he made no guarantees as to whether Ba'al would be alive.
- Failed a Spot Check: Invoked by Daniel, who grimly fears the SGC didn't get all the Goa'uld-controlled Trust during "Full Alert" as they'd hoped.
- Full-Circle Revolution: Played with a bit when it comes to the Free Jaffa; one of Gerak's underlings is reluctant to use the cattle prod on a captive prisoner, pointing out that it was by using such tools that the Goa'uld kept them oppressed. Gerak is having none of it, however, and states that that just makes it fitting for them to use if for their own ends.
- Gas Leak Cover Up: The government's cover story for the Halcyon Tower disappearing is a "gas line explosion".
- Going Native: Ba'al has adapted astonishingly well to Earth in less than a year (arguably better than Teal'c, who's been here for years). He's running his own business, playing bartender, complaining about cable, enjoying Chinese takeout...
- Ba'al even admits in his recorded threat to the SGC that now that he's spent extended time on Earth, he's actually grown to enjoy the planet and is grateful in hindsight that the Goa'uld never conquered or destroyed it.
- Hidden in Plain Sight: Teal'c mentions the trope by name when he realizes Gerak's forces are hiding on the far side of the moon. Ba'al turning an entire building into a bomb probably also counts.
- Knight Templar: Gerak.
- Look Both Ways: The episode opens with a lone Jaffa running for his life through a heavily wooded area, only to stumble out onto a road and immediately be hit by a car, establishing the planet in question as Earth.
- Lopsided Dichotomy:Mitchell: Witnesses?Daniel: One. Some guy who was working overtime and spent most of the firefight under his desk but was able to provide a description of three individuals: big, tattooed, chainmail pants.Mitchell: So, it's either our Jaffa or KISS is back on tour.
- Politeness Judo: Ba'al's assistant does this while fielding Carter's questioning.
- Private Detective: Alex Jameson's wife mentions that she hired one when her husband started acting strange, suspecting him of having an affair, only for the PI to return all her money and tell her to drop the case.
- Pun-Based Title: The title of the episode is a play on both the literary term "deus ex machina" and Ba'al's status as an "ex-deus" or ex-god.
- Putting the Band Back Together: Mitchell finally gets his wish as Daniel, Carter and Teal'c all officially re-join SG-1, Lampshaded by Mitchell replacing their SCG shoulder patches with SG-1 ones.
- Relocating the Explosion: The Prometheus beams the building that Ba'al had built as a naquadah-enhanced bomb into space, where it detonates harmlessly.
- Right Under Their Noses: It's revealed that Ba'al has been hiding out on Earth since his fleet was destroyed at the battle of Dakara.
- Send in the Clones: The team discovers that Ba'al has been experimenting with cloning, and the final scene shows that there are at least four of him on Earth.
- Sharp-Dressed Man: Ba'al seems to have swapped the usual
Fashion-Victim Villain attire of the Goa'uld for expensive suits in order to blend in on Earth as the CEO of a major corporation. - Surprisingly Realistic Outcome: There were no guarantee that all of the Goa'uld-controlled Trust members were aboard Osiris' ship when it was destroyed during "Full Alert". There were cells the SGC missed (and which Ba'al has taken control of in the interim).
- That's No Moon:Carter: The bomb isn't in the building, sir. The bomb is the building.
- Ungrateful Bastard: The Jaffa High Council under Gerak's rule turn on Teal'c due to his affiliation with Earth, despite his instrumental role in the Jaffa rebellion, and treat their former allies with suspicion and contempt.
- Villain with Good Publicity: Ba'al invokes this by holding a press conference as the new CEO of Hammel Technologies, making it virtually impossible for the team to move against him without creating a media frenzy and risking exposing the program.
- Wham Shot: When it's revealed that Ba'al is on Earth. And again when it's revealed there are at least four of him on Earth.
