"You can never go home."
— Gerren, to O'Neill.
O'Neill is stranded on the planet Edora after the Stargate is buried by a meteor strike. As the rest of the team frantically searches for a way to bring him home, O'Neill adjusts to a simpler way of life and begins a relationship with a local woman named Laira.
"A Hundred Days" provides examples of the following tropes:
- Alien Sky: Edora has two moons.
- Asteroid Thicket: Edora's orbit passes through an asteroid belt every year, causing the meteor showers.
- Bittersweet Ending: O'Neill gets to go home, but he has to leave Laira and the life he made for himself on Edora behind.
- Cassandra Truth: When the team warns the locals about the impending disaster, many of them believe it to be a lie as the meteor showers have always been harmless in their lifetime. Even when the meteors begin to strike the ground and cause damage, a third of the population still chooses to stay behind rather than evacuating with the rest.
- Continuity Nod: Carter is able to melt through the crust of naquadah that's formed over the buried Stargate using the same technique employed by Sokar to try and penetrate the Earth iris in "Serpent's Song".
- Determinator: Teal'c makes what could well be a one-way trip through the gate into an underground cavern with a limited supply of oxygen, where he proceeds to blast his way through several layers of rock in order to get to O'Neill.O'Neill: Teal'c, you are one stubborn son of a bitch!
- Gadgeteer Genius: Carter builds a particle beam accelerator from scratch in three months.
- Going Native: By the end of his time on Edora, O'Neill has fully embraced the way of life there and appears ready to settle down with Laira. He even tells her to throw out his old clothes and equipment, shortly before The Cavalry arrives.
- Homeworld Evacuation: The team organizes an evacuation of the Edorans to Earth once they realize the scale of the latest meteor strike.
- New Child Left Behind: Possibly. Laira asks O'Neill to give her a child after she deems that he's let go of his old life; it's implied they sleep together, and though it's not stated either way whether she gets pregnant as a result, the way in the final shot both hands go to her belly does at least imply it.
- No One Gets Left Behind: Averted; the rest of the team is forced to flee as the meteors begin to strike closer to the Stargate with O'Neill nowhere in sight, though they spend the remainder of the episode searching for ways to reach him.
- Oh, Crap!:
- When the team realize the "fire rain" is not as harmless as they've been led to believe.
- Happens again with O'Neill on the planet after the bombardment when a villager tells him of being where the Stargate used to be. O'Neill rushes to the spot to see nothing but rock and a crater.
- One-Product Planet: The main reason Earth is keen to form a treaty with Edora is that the soil is rich in naquadah.
- Ship Tease: Carter sort-of indicates to Fraiser that she might have feelings for O'Neill, and looks uncomfortable when she sees him saying his goodbyes to Laira at the end.Fraiser: You miss him.Carter: Yeah.Fraiser: ...Is this going to be a problem?Carter: No. No, of course not.
- Temporary Love Interest: O'Neill forms a relationship with Laira during his time on her planet, which naturally comes to an end by the episode's climax. He does promise to visit again sometime in the future, but he never does, at least not that we see. Although in "Shades of Grey", O'Neill, after temporarily retiring from the military, asks General Hammond for one last favor, to retire to Edora in order to be with Laira. It's a ruse, and as far as we know he never does see her again.
- Time Skip: The episode's time frame skips ahead from a few days after O'Neill is first stranded on Edora to three months later, when he has gone fully native.
- Title Drop: Laira mentions that she mourned her husband's death for a hundred days. Also, the time span of the episode is a little more than three months.
- Ungrateful Bastard: One of the Edorans blames O'Neill for their population being decimated, despite the fact that evacuating the others most likely saved their lives.
- Vicious Cycle: The meteor shower happens every year and reaches apocalyptic proportions every 150 years.
