The stargate establishes a connection to a planet caught in the gravity of a black hole and will not disengage, trapping the base in a time dilation field and threatening to pull earth into the black hole unless the gate can be shut down.
First appearance of Major Paul Davis.
"A Matter of Time" provides examples of the following tropes:
- Admiring the Abomination: Carter is pretty excited by the black hole at first, until the gravity of the situation (no pun intended) becomes clear.
- Bottle Episode: Takes place almost entirely inside the base or just outside.
- But What About the Astronauts?: It's mentioned a few times that Daniel is still off-world, along with a couple of other SG teams, and that they, at least, will survive even if earth is sucked into the black hole.
- Cold Open: The episode opens with a shot of a sun being pulled into the black hole, followed by SG-10 on the surface of the planet, running in slow motion in a desperate attempt to reach the stargate.
- Cruel and Unusual Death: SG-10 is stranded on a planet caught in the gravity of the black hole, desperately trying to dial earth but unable to do so fast enough as time slows to a crawl. And that's not even the worst of it: Carter spells out the process of spaghettification for O'Neill and Hammond, explaining that they will eventually be pulled apart atom by atom.
- Dark and Troubled Past: O'Neill mentions that he spent four months in an Iraqi prison after a black ops mission gone wrong.
- Eureka Moment: Hammond mentioning the second stargate prompts Carter to realize that if they detonate a bomb close enough to the wormhole, the matter stream should jump to another planet and allow them to safely disengage.
- Gravity Sucks: Played straight, with larger and larger objects getting sucked into the wormhole from ever-greater distances as the gravitational field increases.
- Guilt Complex: It's made pretty clear that O'Neill blames himself for Major Boyd's fate, echoing Cromwell's guilt over leaving O'Neill in Iraq.
- Hollywood Healing: Teal'c receives a pretty nasty burn near the beginning of the episode, but is almost entirely healed by the end. Justified due to the time dilation effects of the black hole. Also explained by Healing Factor due to his symbiote.
- Layman's Terms: Carter trying to explain the concept of wormholes to O'Neill at the beginning of the episode.
- No One Gets Left Behind: Subverted; it's revealed that Cromwell left O'Neill behind on a Special Forces mission in Iraq some years ago after mistakenly believing him to be dead, allowing him to get captured. Neither one of them has forgiven him for this.O'Neill: What happened to "nobody gets left behind"?
- Oh, Crap!: Happens at least twice:
- When O'Neill, Carter and Hammond see the black hole on the probe footage and realize just what exactly is is that has Boyd so scared.
- When Carter watches her dogtags get sucked into the event horizon and realizes that the gravity from the black hole is able to travel through the outgoing wormhole to earth.
- Out of Focus: Daniel is absent for most of the episode, only making a brief appearance at the very end to visit O'Neill in the infirmary.
- The Political Officer: Major Davis is introduced as the official liaison between Washington and the SGC, in a much more sympathetic portrayal than most examples.
- Red Shirt: SG-10 and Colonel Cromwell.
- Redemption Equals Death: Unwilling to let history repeat itself, Cromwell refuses to arm the bomb while O'Neill is so close to the black hole. Naturally, this results in him getting sucked in when an errant shard of glass cuts through his safety rope.
- Self-Destruct Mechanism: Initially the orders from the White House are to set the base self-destruct, but Carter is convinced that this will only make the situation worse by blowing up the mountain while leaving the stargate - and by extension, the wormhole - intact. Eventually she comes up with the alternative solution of detonating a smaller charge close enough to the wormhole that it will cause the matter stream to jump.
- Slow Motion: Used to demonstrate how time slows down the closer a person is to the black hole.
- Techno Babble: A lot in this episode, as Carter attempts to explain the concept of relativity to everybody else. Hammond probably says it best:Hammond: Captain, relativity gives me a headache.
- Time Dilation: The effect of the black hole's gravity means that time appears to slow down closer to the wormhole, so that Hammond is able to travel to Washington and back for an overnight conference with the President while only minutes appear to pass in the control room. When Daniel returns at the end of the episode, he reveals that two weeks have gone by in the space of what feels like about a day for those inside the mountain.O'Neill: Two weeks? I think I'll sleep in.
- Two-Keyed Lock: Two officers are required to enter a passcode in order to set the self-destruct.
- Unrealistic Black Hole: Actually averted, for the most part; barring some slight liberties taken for dramatic effect, the science is generally pretty sound. Carter makes a comment that the time dilation is happening in advance of the gravity waves, when they should be happening at the same time (which is what is currently believed in real science). Her explanation (the only one we get) is that it's "probably a lensing effect of the Stargate itself".
- What the Hell, Hero?: O'Neill chews Carter out over her initial excitement at the prospect of getting to watch spaghettification firsthand.Carter: By some fluke of the stargate, we have the opportunity to witness something which that laws of physics dictate we should never be able to see.O'Neill: We are witnessing good men die in slow motion, Captain.