“Forsaken” is episode eighteen of season six of Stargate SG-1.
SG-1 are on a planet observing a gas nebula around a dying star when O’Neill comes across a photograph. Which seems odd. Then Jonas and Teal’c discover a crashed starship of unknown origin, with markings on it that Jonas says have a Celtic style. Then they discover three armed survivors of the crash.
The survivors would like a lift in SG-1’s starship but, of course, they don’t actually have one, having come through the stargate. They do offer to see if they can help fix the ship.
The survivors have awfully unwieldy looking weapons. No matter what, a gun should be easy to use. They aren’t the only people on the planet either – there are some others who are made out to be rather nasty. O’Neill doesn’t trust them, but that’s pretty much his ground state.