Principal setting: Germantown, Maryland; Steveston, Massachusetts.
In the scene of the first victim, as Agent Mulder was carefully studying the body with a cotton tip, you can see the actor playing the victim's closed eyes moving under his eyelids. Somebody seems to be ticklish when they're playing dead.
A painting by H.R. Giger can be seen on a wall in the background of the night club twice.
Revealing Mistakes: Watch the opening scene as the camera pans through the night club. If you look very closely (if you have the DVD you can play it frame by frame) you will be able to clearly see the steadi-cam operator in the reflection of the stairs as the camera goes up them to the next level. He seems to be wearing a beige t-shirt and blue jeans.
Continuity: After the part where the head Kindred woman tells Mulder and Scully "I asked you not to interfere", Mulder leads Scully away. From one camera angle, he is leading her away by the hand. In the same scene, but from a different camera angle, he has his arm around her. When we go back to the first camera angle, he is once again leading her away by the hand.
Mulder: The Addams family finds religion.
Scully: Take me back to the 20th century.
Mulder: You believe all that back there, Scully?
Scully: Believe all what?
Mulder: All that "we take care of our own" business?
Scully: Well, they better take care of their own or that man at the dinner table is a dead man.
Mulder: I think it was all an elaborate act.
Scully: What? The choking?
Mulder: No, all this simple life, living from abundance crap. These people know something, Scully. You can see it in their eyes - the way they look at one another.
Scully: You think there's a new drug on the streets?
Mulder: The oldest drug, not even illegal. Each body showed the presence of huge amounts of pheromones.
Scully: The chemicals animals secrete? You mean, sexual attractants?
Mulder: Radar love. Only about a hundred times stronger than found anywhere in nature, strong enough to product anaphylactic shock or a coronary.
Scully: So you think somebody is synthesizing them?
Mulder: It's been done, but in nowhere near these concentrations and hold on to your hat, Scully, 'cause you're gonna love this. The pheromones we're talking about - they contain human DNA.
Scully: Well, there's still a question as to whether humans can produce pheromones. So how can that be?
Mulder: I don't know. But if it's true, then this guy is a walking aphrodysiac. He's the ultimate sex magnet.
Scully: I don't understand, how can they just disappear? They have no means of transportation.
Mulder: No earthly means of transportation.
Scully: We can't rule out the possibility that who we're looking for is a transvestite.
Mulder: I think Don Juan in there knows the difference between the male and female of the species.
Michael: The club scene used to be so simple. It's off the record.
Mulder: (gives salute) Scout's honor.
Mulder: I know what I saw, Scully. And I saw you about to do the 'wild thing' with some stranger.
Mulder: [upon seeing the abandoned Kindred home] Maybe they went to the movies.
Scully: So what is our profile of the killer? "Indeterminate height, weight, sex. Unarmed, but extremely attractive?"
Mulder: It gets weirder.
Scully: There's something up there, Mulder.
Mulder: Oh, I've been saying that for years.
Nicholas Lea who played the hospitalized victim in this episode would go on to return to the show as a different and much more major character, Alex Krycek.
The setting of this episode (Steveston, Massachusetts) was named after a real town south of Vancouver that is often used by the crew for location work.
In the original script, the teaser featured a man whose crotch started to rot away.
The music used for the disco in the opening scene is from Mark Snow's theme music for the television movie In the Line of Duty: Street War.
This is the first episode where the credit "Music by Mark Snow" appears during the opening credits and not the closing credits.
Kate Twa, who plays Female Marty in this episode, will return to play Detective Kelly Ryan in the season two episode "Soft Light."
Mulder: The Addams family finds religion.
The Addams Family is a creation of cartoonist Charles Addams about a bizarre family who delight in all things frightening and macabre. They first appeared in the 1930s as a cartoon in The New Yorker and later as part of a popular 1960's television series. In the 1990's the comic was adapted for a series of films.