- Weir: I dont see any volcano.McKay: Because youre standing inside it right now.
The Atlantis team answers a call for help from the world of Taranis, where the locals are having trouble with their shield generators. Taranis turns out to be protected by Ancient technology powered not by a ZPM, but by the geothermal energy of the planet iself. The Ancient base of operations is built inside the caldera of a currently inactive supervolcano for this reason. In recent days, however, there have been ever-increasing tremors causing shield failure, so McKay gets to work with hot Taranian scientist Dr. Norina Pero to help put things right.
It turns out the Taranians have more than just cool shields. The Taranian Chancellor Lycus shows a delighted Col. Sheppard the base's hangar bay - and contained within it, a battle cruiser identical to the Aurora, called the Hippoforalkus. Which of course Sheppard immediately changes to Orion. The happy christening is interrupted by urgent news from McKay - powering the shields constantly for the last year (that is, since the Wraith woke up and went on a rampage) has caused the supervolcano to come back to life several thousand years early. It could blow any time now, taking half the continent with it and filling the atmosphere with ash - which will in turn blot out the sun and choke out all life for the forseeable future. It's time to evacuate all the Taranians to Atlantis - now.
The Chancellor is understandably suspicious that impending planetary doom turned up just after he showed Sheppard an impossibly cool ship that he could desperately use - but he consents to the evacuation anyway. McKay and Norina try to get the Orion working while the rest of the population heads for the stargate. Only the first wave of Taranians is able to escape to Atlantis before another tremor opens up a fissure - and the gate is sucked down into molten lava. Being suddenly cut off from his people in a strange place makes Chancellor Lycos even more suspicious, and Weir sends the Daedalus to investigate.
The Daedalus confirms the disaster and starts to beam up the refugees, but life support issues will require it to make four trips to get everyone out - at 12 hours each. Sheppard does his best to motivate McKay with the threat of impending death and starts moving the remaining refugees onto the Orion - where they are unfortunately shielded from the Daedalus' beam technology. Lava covers the hangar doors, preventing their escape, and it seems impossible to get the Orion's sub-light engines working anyway. When the volcano eventually blows, their shields should be able to hold for a mere 4.1 seconds before they are all horribly incinerated.
Fortunately, when the volcano does blow a few minutes later, it does so with enough force to throw the Orion up into the atmosphere - at which point McKay opens up a hyperspace window sufficient to put them into orbit before the allotted 4 seconds are up. The Daedalus is then able to ferry everyone back to Atlantis at their leisure. The Taranians are safely relocated to a non-exploding planet and in return Chancellor Lycus graciously loans Weir the Orion, to be used in the imminant fight against the Wraith.
- Apocalypse How: Class 5
- Call-Back: To the episode "Trinity":McKay: I have a very firm grasp of Ancient technology.Sheppard: Youve blown up entire planets, Rodney.McKay: That wasnt my fault!Sheppard: Well, it didnt do it by itself!
- Chekhov's Volcano: in fact, it's a supervolcano!
- Crazy Enough to Work: McKay's plan to use the force of the eruption to launch the Orion into hyperspace.
- Exact Time to Failure: both Hermiod, with the eruption, and McKay with the shields.Hermiod: Colonel. I believe the eruption will occur in fifty-two seconds.Caldwell: Are you sure?Hermiod: I would not state it if I wasnt.
- Explosive Overclocking: On a planetary scale; the Taranians turned their geothermal-powered shield generator up to maximum for over a year, then overrode the failsafes without realizing what they were doing. As a result, the dormant supervolcano became active, and triggering an extinction-level event!
- Jerkass: The Taranian Chancellor.
- Jerkass Has a Point: His initial mistrust is understandable, pointing out that it's "highly coincidental" that after discovering they possess an Ancient Warship, the Atlantis team suddenly claims they should evacuate the entire planet. Then seconds after arriving in Atlantis, the shield raises and all attempts to dial back "supposedly" fail, leading him to believe he's being held hostage.
- Pet the Dog: He does later apologise for his behaviour, when it becomes obvious they really are telling the truth and going out of their way to save his people. He later gives them the Orion in exchange for their aid in relocating them and helping them rebuild.
- Just in Time: Sheppard frequently lampshades McKay's ability to save the day with wacky super-science in the nick of time, to motivate him to keep working.
- Hot Scientist: Norina, who has McKay and Sheppard making idiots of themselves for her benefit throughout the entire episode.
- Hypocritical Humor: Sheppard says he should get back to Taranis to stop McKay from getting distracted by the attractive Norina. Later in the same conversation Weir asks about the leader, Lycus, and Sheppard doesnt know how to describe him because, Hes a guy. Didnt pay much attention. Sorry!
- Nice Job Breaking It, Hero!: The Taranians started keeping their shield on full-time after detecting the Wraith were once again active in the galaxy. Ironically this ended up overtaxing the shield, causing the supervolcano under their feet to wake up and forcing them to evacuate. Which leads them to be wiped out a year later by Michael's hybrids in "Vengeance".
- Oh, Crap!: Rodney's reaction to discovering they're inside inside the caldera of a massive supervolcano.
- Mass "Oh, Crap!": Everyone has this reaction after the ground beneath the Stargate causes it to sink into molten lava.
- Shout-Out: The Orion is named for the protagonists' ship in the German cult Sci-Fi series Raumpatrouille - Die phantastischen Abenteuer des Raumschiffes Orion (Space Patrol - The Fantastic Adventures of the Spaceship Orion) from 1966. The 2003 special edition DVD was a gift to director Peter DeLuise from German journalist (and Stargate correspondant) Robert Vogel.
- Sheppard shoots down McKay's suggestion to name the Ancient ship ''Enterprise''.
- That Came Out Wrong: Plenty!McKay: First we need to get off. Er, I mean get off the planet. Then you can be under me. I mean...
- Too Dumb to Live: Vonos, who ignores their repeated warnings to evacuate via the Orion and decides to lead a group to the river, under the insane belief that it will protect them from the lava and by following it to the ocean, this will keep them safe from the poisonous ash cloud and the imminent continent-destroying eruption.Ronon: He thinks he can outrun this thing...
Caldwell: Yours were the only lifesigns on that planet we could detect.
- Even before the eruption, his group's fate is hinted at when Caldwell beams up Ronon and Teyla's group;
- Unfortunate Names: Invoked by Sheppard about the Hippoforalkus. He may have been a great general and had a respected name amongst the Ancients, but it's an awful name when it comes to christening your Cool Starship. Hence why he quickly changes it to the Orion.
- You Look Familiar: Chancellor Lycus is Dr. Warner, Dr. Frazier's predecessor on SG-1.