SG-1 rescue a fleeing man, which is apparently the wrong thing to do as he was a fugitive, and due to differences in the legal system of Hadante and Earth, they end up imprisoned somewhere with a Stargate but no power or DHD. Cue prison episode.
SG-1 makes friends with Linea, who all the others are afraid of. With good reason, it turns out, since her nickname turns out to be "Destroyer of Worlds". She shows them native plants that somehow generate cold fusion power, which SG-1 plan on using to dial out. Daniel has his reservations since she apparently convinces the other prisoners to occasionally commit suicide via kawoosh, but the rest of the team just want out. At the end of the episode she vanishes until next season, when she reappears (sort of) in "Past and Present"
"Prisoners" provides examples of the following tropes:
- Absolute Xenophobe: The Taldor are described as such.
- All Crimes Are Equal: This is how the judicial system on the planet of the week works; all crimes, from trespassing to murder, warrant a sentence of life imprisonment.
- Arson, Murder, and Jaywalking: Explicitly alluded to in the dialog. Linea is in for genocide; SG-1 is in for literally saying hi to a fugitive.
- Bitch in Sheep's Clothing: Linea seems like a kindly old lady; then we find out that she wiped out half the population of an entire planet.
- Choke Holds: Daniel and O'Neill are both very nearly strangled to death when the other prisoners decide they're upsetting the balance of power. Carter escapes because she's under Linea's protection, while Teal'c is Teal'c.
- Continuity Nod: The team realizes that they will be able to escape if they can find a power source to dial the gate manually, something they've done in the past.
- Dark and Troubled Past: O'Neill mentions that this isn't his first time in the big house. (In a later episode, "A Matter of Time", it's revealed that O'Neill spent four months in an Iraqi prison as a result of a bungled mission during The Gulf War.)
- The Dreaded: Though she acts as if she's a kindly old lady, it's obvious from the start that Linea is nothing of sort because the rest of the prisoners are terrified of her.
- Exact Words: Linea never actually lies, she just fails to mention the part where she was the one who started the plague in the first place.
- Frontline General: Hammond makes his first trip through the gate to meet the Taldor in person and try to bargain for SG-1's freedom.
- Forgotten Phlebotinum: It seems like plants that can generate cold fusion would be an insanely useful thing to have around, but the technology is never even mentioned again.
- Great Escape: The team is able to pull off their breakout relatively quickly with the help of Linea.
- Mad Scientist: Linea is shown to have an incredible gift for science; unfortunately, she uses it to create planet-destroying plagues.
- Makes Us Even: Linea states that SG-1 providing her with the means to freedom makes them even for her assistance in breaking them out of prison, in a particularly creepy message she sends through the base computers after making her escape:"THANK YOU FOR YOUR KINDNESS.ALL DEBTS HAVE NOW BEEN PAID."
- Mistaken for Badass: The other prisoners think that Daniel managed to overpower and kill Vishnar during their "fight" due to Linea covertly taking down the latter with some MacGuffin or other while nobody was paying attention.
- Names to Run Away from Really Fast: 'The Destroyer of Worlds'.
- Nice Job Breaking It, Hero!: In helping Linea escape from Hadante and proving her with the gate addresses, the heroes inadvertently set a genocidal maniac loose on the galaxy. Oops.
- Noodle Incident: We catch the tail end of a fight between Teal'c and another inmate, which mostly consists of Teal'c choking the life out of the other guy while Daniel nervously points out that he's probably had enough. No explanation is given for this.
- The Old Convict: Linea.
- Penal Colony: Hadante is a prison planet. Daniel actually likens it to Botany Bay at one point.
- Prison Episode: Duh.
- Prison Rape: Alluded to; after the team is first sent to the prison at the beginning of the episode, the other inmates immediately gather round and start doing some very creepy whistling thing. Carter is grabbed by Vishnar, at which point Linea shows up and declares Carter under her protection, stating that she "knows how hard it is to be a woman on Hadante". There's also O'Neill taking Daniel's glasses off, with this sage piece of advice:"You gotta trust me on this. Signs of weakness are not a good thing in prison."
- Rhetorical Question Blunder:O'Neill: I'm gonna go ahead and assume you've never actually been in prison before.Daniel: Oh right, and you have?O'Neill: Oh yeah.
- Scary Black Man: Invoked by O'Neill telling to Teal'c to "look scary and take point."
- Smoldering Shoes: The team are greeted with a pair of these on their revival, their former owner having been disintegrated by the "kawoosh" of the stargate as it activated. They later find out that some of the prisoners would deliberately stand in front of the vortex in the hope that it would set them free.
- Take Me Instead: Thwarted. Hammond offers himself to the Taldor in exchange for SG-1, but they decide that he is innocent according to their byzantine rules.
- The Voice: The Taldor deliberately keep their faces hidden and are only "seen" as ominous, disembodied voices.