SG-1 finds a planet inhabited by Native American Indians, protected by spirits who are actually advanced alien shapeshifters. The Pentagon learns that the phrase "what they don't know won't hurt them" is a really
bad thing to say when the people you're trying to hoodwink are guarded by a very powerful alien species capable of, once again, walking through walls and turning invisible.
"Spirits" provides examples of the following tropes:
- A Form You Are Comfortable With: The Sufficiently Advanced Aliens take on the form of the Salish spirits for precisely this reason. Subverted at the end, however, when Xe'ls invites Tonane and his people to view them in their true form.
- Animorphism: The spirits are able to turn into animals as well as humans.
- Annoying Arrows: Averted; O'Neill is shown to be in a fair amount of pain after being shot through the arm with an arrow, enough so that he has to miss out on the mission and still has his arm in a sling when the others return. Granted, it was a trinium arrow.
- Arbitrary Skepticism: Given everything else they've encountered, you'd think the team wouldn't be quite so quick to write off the possibility that Tonane's spirits could be real.
- Benevolent Precursors: The spirits are this for the Salish people.
Tonane: They don't rule us. They protect us.
- First Name Basis: Played with in this exchange.
Carter: Captain Samantha Carter, SGC.
Tonane: Long name.
Carter: How about we just go with Sam, then?
Carter: And these are my friends, Dr. Daniel Jackson...
Daniel: ...Daniel's fine.
- History Repeats: O'Neill disgustedly points out that the US military stealing resources from Native American settlements is not exactly an unfamiliar story.
- I Gave My Word: Subverted:
Teal'c: The demon will cause you no harm. I give you my word.
Tonane: Normally that would mean a great deal to me. But how do I know the value of your word? We've only just met.
- Instant Sedation: Carter, Daniel and Teal'c pass out almost instantly after the natives shoot them with tranquilizer darts.
- No Longer with Us: When Tonane tells the team that SG-11 are "with the spirits" they immediately assume the worst, but he's being literal.
- Out-of-Character Alert: O'Neill is able to tell straight away that Dr. Warner - actually Xe'ls - is Not Himself.
- Outgrown Such Silly Superstitions:
Teal'c: I thought I heard something.
Teal'c: Jaffa do not believe in such things.
- Rubber-Forehead Aliens: The 'spirits' in their true form are essentially humans with fish-like gills in the middle of their faces where there noses should be.
- Shapeshifting: The spirits are able to change form into any human or animal at will.
- Something Only They Would Say: Subverted, or parodied, or... something with Jack and Daniel on two separate occasions:
Daniel: Jack! Are you you?
O'Neill: Yes. Are you?
O'Neill: ...Never mind.
O'Neill: How do I know you're the real Daniel?
O'Neill: ...Yeah, okay.
- Unobtainium: Trinium, which the Pentagon is apparently so desperate to get their hands on that their orders are to mine it without the knowledge or consent of the natives.
- Transplanted Humans: The native inhabitants of the Planet of the Week are transplanted Native Americans, specifically Salish.
- You Are in Command Now: Carter leads the mission due to O'Neill being temporarily incapacitated.
O'Neill: Your first command. Cool.