Sight Unseen

"Sight Unseen" is the thirteenth episode of the sixth season of Stargate SG-1.

Synopsis
After returning from a planet, Jonas Quinn is startled to see some bugs that no one else can see. Soon other SGC personnel also start seeing the bugs. Attempts to contain the situation go badly as civilians begin seeing the bugs.

Plot
SG-1 comes back to Stargate Command with a strange device which was built by the Ancients. While they talk about the device, Jonas Quinn suddenly sees a large, flying, insect-like being, which seems to fly through the wall. However, no one else witnessed the being. Nevertheless, Major General George S. Hammond orders the lockdown of the base. The searches turn up nothing, so Jonas' comrades think he might be having hallucinations.

While Colonel Jack O'Neill leaves the base to go fishing, Major Samantha Carter and Jonas examine the device. During their research, Jonas again sees a large insect and is immediately examined by Dr. Janet Fraiser. Nothing unusual is found in the scans, but nevertheless, Hammond removes Jonas from active duty.

While talking with Teal'c, Jonas sees another large insect, however, this time Teal'c sees it too. Outside the base, O'Neill, while filling his car at a local gas station, sees an insect himself, pulls a gun, and shoots at it, much to the shock of the owner of the gas station. O'Neill calls Hammond to report the incident, only to learn several people in the base have begun to see the creatures themselves. In the SGC, Jonas and Carter again study the Ancient device and discover that it allows people to see entities from another dimension, or as Carter calls it, an "interdimensional bleed-through" effect. However, they are unable to ascertain how the machine affects people in this way, so they deactivate it by removing the power core, thus hoping to stop its effect.

Later, Jonas and Carter talk with Teal'c in the mess hall when a woman suddenly screams (it is assumed she saw one of the insects). Because of this, SG-1 (without O'Neill) brings the device back to its home planet. The insects continue to appear, so SG-1 takes it back to Earth again. They conclude that the device not only attracts the insects, but allows people to see the bugs by imparting a slight electrical charge which can then be passed from person to person. Hammond has Colorado Springs quarantined to limit the device's effect. Several military personnel are stationed in the nearby area, using the cover story of a chemical spill that can cause hallucinogenic side effects.

For a third time, Jonas and Carter inspect the device and deduce that they have to rearrange the device's control crystals to produce the desired "antidote." Meanwhile, the owner of the gas station, who O'Neill visited earlier, disbelieves the cover story and runs away. O'Neill pauses before pursuing the man, as a car crashes into a sign due to the driver seeing an interdimensional bug on his windshield.

Back at SGC, Carter and Jonas finally discover the correct crystal arrangement and begin to pass on the “cure” from person to person. However, the owner of the gas station, named Vernon Sharpe, eludes authorities and hitchhikes to the airport. Meanwhile, Carter and Jonas find out more about Vernon through his grandmother to narrow down where Vernon might be. She reveals that Vernon doubts the cover-story because of his prior experience in the Gulf War, where he believed the military experimented on the troops with toxic chemicals.

Vernon arrives at the airport and unsuccessfully tries to board a plane before the military cancels all flights and shuts down the airport. O'Neill drives to the airport in pursuit. Vernon, now scared out of his wits, hides himself in a nearby hangar. O'Neill locates Vernon and convinces him that everything will be safe, creating a cover story for the cover story (the beings are aliens from the planet Melmac). Vernon agrees to keep quiet and O'Neill cures him of the device's effects.

Notable Quotes
Hammond: Welcome home, SG-1. How did it go?

O'Neill: Ah, General, you know how I love those sandy planets.

Teal'c: The wind was most pleasant.

O'Neill: Jaffa sarcasm at its finest, general.

Carter: You only saw a flash of this creature. Are you sure it wasn't some kind of hallucination?

Jonas: You're suggesting I'm delusional?

O'Neill: No. No, it's just... possible... that you were seeing something that wasn't entirely... yes, that's what we're suggesting.

Carter: (to Jonas) Colonel O'Neill asked me to go fishing with him, but to be honset, I find [studying alien technology] more relaxing.

Teal'c: (to Jonas) Colonel O'Neill requested that I accompany him on a fishing expedition.

Jonas: Ahh, I guess I'm the only one he didn't invite.

Teal'c: You are not permitted to leave the base.

Jonas: But still...

Teal'c: Be extremely happy that he did not ask.

Jonas: Why, you don't like fishing?

Teal'c: No.

Mrs. Sharpe: (to Sam and Jonas) Well, you seem like a nice enough couple.

Jonas: Oh, we're not...

(Sam stops Jonas by putting her hand on his hand)

Carter: Please, we really want to help.

(Jonas puts his other hand on Sam's hand to keep up the act)

Vernon: So what planet are they from?

O'Neill: Who?

Vernon: The aliens.

O'Neill: Oh. Ah, a place called Melmac.

Vernon: Isn't that where ALF is from?

O'Neill: Who?

Vernon: ALF, you know, on TV, the puppet.

O'Neill: Never saw it.

Vernon: No kidding?

Goofs

 * The rightmost chest X-ray film in the Dr. Janet Frasier's office is upside down.
 * When Colonel Jack O'Neill puts his hand on Vernon Sharpe's shoulder, from one camera angle his hand is a few inches away from the neck, but from the other his hand is touching the neck.
 * When Jonas Quinn is studying the crystals from the device there is Goa'uld writing on them, not Ancient.

In other languages

 * French: Hallucinations (Hallucinations )
 * Italian: Visioni Invisibili (Invisible Visions)
 * Spanish: Ilusiones (Illusions)
 * German: Die Unsichtbaren (The Invisible)
 * Czech: Karanténa (Quarantine)