In many ways, “The Enemy Within” is the spiritual forerunner to Battlestar Galactica‘s “36 Hours,” also the first non-introductory episode in that series. The Goa’uld are battering the gate every two hours, and though the iris keeps them at bay, no one can sleep — each attack necessitates a full lockdown and the start of the fully-alarmed self-destruct sequence.  Meanwhile, it starts to become clear that the true enemy is not the one knocking at the door, but the one that’s already gotten in.

But unlike “36 Hours”, this isn’t a particularly memorable episode of SG-1, as it never hides that it’s fundamentally setup. Now, to be fair, that setup is necessary. Without some reason to lower their expectations of what would happen if Sha’re and Skaara were recovered, Daniel and Jack’s most plausible arc would be taking increasingly stupid risks to find them quickly, in the hope that ridding them of the Goa’ulds would be easy. Meanwhile, fans of the movie would be wondering why Kawalsky got no screen time and why Teal’c wasn’t in Area 51. No one would be able to settle in for the long haul of S1 exploration episodes.

So the writers address these issues, methodically, as though they’re checking tasks off a list. Kawalsky can’t be a main character because he dies a gruesome death. Daniel and Jack have less reason to try to find their loved ones quickly, since it’s now clear that the Goa’uld take over in an instant and are extremely difficult to remove. Finally, Teal’c’s unquestioning cooperation with the SGC — including letting them experiment on the symbiont that, you know, keeps him alive — gives Hammond the justification he needs to ensure that Teal’c stays on SG-1. Check, check, check.

This workmanlike plot does have traces of sophistication around the edges. The titular enemy nominally refers to the Goa’uld inside Kawalsky, but the episode parallels this with an emotional enemy embodied by Colonel Kennedy. As the episode unfolds, it becomes clear that Kennedy’s eagerness to get involved with the SGC isn’t constrained by quaint notions of rights or even common sense. When he wants to study Teal’c, it’s because the Goa’uld are such a huge threat that Teal’c’s rights must be disregarded; but when Kawalsky’s operation might fail, suddenly the Goa’uld is another intelligent life whose rights should be equally considered, and why not let it go back through the Stargate to show good faith? As a kid, I considered this whiplash ridiculous and almost comically bad writing. As an adult, I’ve unfortunately worked with people like Kennedy (though with much lower stakes) and now I find his character prescient and accurately observed.

Also accurately observed, but less resonant, is how Teal’c deals with these problems. As an experienced military commander, he understands that surrendering himself doesn’t guarantee immediate trust, and that the best thing to do is keep his head down and cooperate. In fact, the only time he shows even a flash of emotion is when O’Neill and Kennedy keep apologizing for not trusting him. (I sympathize — I actually had a hard time watching Jack’s shamefaced justifications to Teal’c throughout the episode, because I’ve been through way too many similar conversations with people who couldn’t figure out how to admit their lack of control.) But since cooperating is so straightforward for him, watching him do it isn’t particularly compelling.

The real momentum in the episode is supposed to come from Kawalsky’s plot. Will they be able to get the Goa’uld out of him? What does it feel like to be possessed by one? How long can a person resist being taken over completely? Jay Acovone does a pretty good job of portraying Kawalsky’s increasing disorientation and helplessness, but ultimately there are no real surprises. It seems you just black out for the duration of the possession, and then feel pretty bad about it afterwards. Also, you’re probably stuck with it. The only interesting part is that Kawalsky’s Goa’uld is able to undergo some kind of molting within his body in order to resist the surgery. Would an adult Goa’uld be able to do that? Could this Goa’uld do it more than once? I understand why this line of questioning might not be immediately pursued, since the only way to do that would be to kill Teal’c, but the total lack of follow-up is jarring.

All this contributes to perhaps the strangest thing about “The Enemy Within,” which is its tonal distinction from the rest of the series. There are very, very few SG-1 episodes that end on such a grim note. In fact, it’s grim twice over: not only does Kawalsky die, but the murder weapon is the Stargate itself. That’s heavy stuff, given that half the subtext in the series is that the Stargate is an unalloyed good that just sometimes leads the unwary to something bad. I mean, the episode where they direct-dial a black hole is less dark than this. Perhaps this episode was sort of a practice run for the writers, a chance for them to experiment with tone before starting on the meat of the season. Thankfully, as we’ll see next week, it seems they learned the right lessons.

Stray observations:

• “General, you know what I went and did? I told Teal’c how we all respect a person’s rights in this country.”
• It goes by quick, but when the doctor tells Teal’c to keep his fingers crossed, he very solemnly crosses both of them and keeps them there.
• “That’s fantastic. If we can reverse what happened to the Major, then there’s still a chance for Sha’re.” Something about this line, or maybe the line reading, rubbed me the wrong way. We get that she’s your wife, Daniel, but how about worrying about the guy currently on the operating table?
• Dear SGC surgeon, why would you think Kowalski’s fit wasn’t anything you did when you just severed the connections a mind-controlling parasite had to his brain?
• “You cannot pass.” If only Teal’c had had his staff weapon, he could have gone full Gandalf.