Mulder and Scully go undercover as a married couple in a gated community to investigate the mysterious disappearances of neighbors who didn't conform.
Disgruntled homeowner Dave Kline arrives home to find his neighbor Win Shroeder has repainted his mailbox from "desert sienna" to "desert sage" to comply with homeowners association rules. His wife Nancy tells him to calm down and that rules are rules. However, in the mailbox was a package from an unknown person, containing a tacky windmill which Kline puts on the roof to annoy the neighbors. While in bed that night, Kline hears an intruder in the house. He goes to investigate while his wife stays in bed. A creature attacks Kline and eventually Nancy as well.
After the Klines' disappearance without a trace from their planned residential community (one of many disappearing couples over the years), Mulder and Scully go undercover as the new homeowners moving into the dead couple's house: Rob and Laura Petrie (the fictitious name of the couple featured on the Dick Van Dyke Show). Mulder is unhappy with the assignment, believing it is a waste of their time since they were just reinstated to the X-Files, and continuously makes jokes, accusing Scully of just wanting to "play house."
The members of the community immediately take an interest in the new couple, with everyone pitching in to make sure they are moved in before 6:00 p.m. (community rules), and Win Shroeder nervously tucks away Mulder's basketball hoop into the garage, promising he could talk to the president of the homeowner's association and perhaps get special permission. After the move-in, Mulder and Scully begin searching the house, which has been scrubbed clean. They find what appears to be blood on a blade of the ceiling fan.
When Big Mike, one of the neighbors, wants to let the "Petries" in on the "consequences" of breaking the community rules, the HOA president Gene Gogolak describes him as "a weak link." That night, he finds his outdoor light burned out. Although he frantically replaces the light bulb, a monster attacks him as he shouts, "I fixed it! I fixed it!"
The next day, Shroeder hoses Big Mike's blood from his porch, where he encounters Mulder and Scully. He asks the couple over for dinner, where Mulder and Scully probe the Shroeders for information on the community and Big Mike's whereabouts. Mulder continues to torment Scully by telling the Shroeders they met at a UFO conference, and "Laura" is a "new-ager." Scully and Cami Shroeder take an after-dinner walk with the Shroeders' dog Scruffy, who runs off into a storm drain. While Scully looks for Scruffy, she finds Big Mike's necklace and a substance on Scruffy's face that looks like blood.Back at "their house," Mulder and Scully find living together challenging, as Mulder doesn't "follow the rules" and Scully would "fit in well" at Arcadia. They discuss possible motives for the murders, and Scully decides to have the substances analyzed in San Diego. Mulder decides to test his theories that noncompliance with the community rules is the motive.
The next day, Mulder sticks a pink flamingo in the yard, which promptly disappears without Mulder seeing who did it. Next, he messes with the mailbox and watches out the door to see who fixes it. After hours of watching, he finally has to use the restroom. When he comes back, the mailbox is repaired and a note inside says, "Be like the others... before it gets dark." After dark, Mulder brings out his basketball hoop, and Shroeder runs over to frantically argue with Mulder to put it away. Meanwhile, something comes out of the grass at Mrs. Shroeder, who screams. Mulder chases it away, but they all notice their light has burned out. The basketball goal is put back in the garage by an unknown person, and the door closed. Scully returns "home" to hear a creaking upstairs, but Mulder doesn't answer. Mulder is still outside looking for the creature, and digs around in the yard. Scully searches the house, armed with a fireplace poker and nearly hits Mulder as he comes in downstairs. Mulder admits to Scully that this is an X-File after all.
Shroeder confronts Gogolak, accusing him of sabotaging his light, the same thing he had him do to Big Mike. Instead, he's told "Rob Petrie" is the real problem. Meanwhile, Mulder believes the creature moves through the yard, under the grass. Scully shares her lab results: the "blood" on the ceiling fan and on the dog isn't blood at all, but grime, as the neighborhood is built on top of an old landfill. Mulder believes the Klines were buried in their yard, so the next day he gets a bulldozer to dig up the front yard, telling the neighbors he's putting in a "reflecting pool," which isn't against the community rules. They don't find the Klines, but they do find the tacky windmill that had been mysteriously delivered to the Klines before they died. The windmill bears a label from Gogolak's company. Mulder says they need to get an excavation team out there to dig deeper. Meanwhile, a creature stirs in the pit they've dug.As Scully calls for a forensic team to come out there immediately, she hears something in the house. She goes for her gun in the dresser drawer but finds it missing. As the creature comes up the stairs, a bloodied Big Mike grabs Scully and tells her to get out, that "it's coming" for her. He tells her they (the original homeowners) created the creature but can't stop it, and he admits he tried to do the same thing to Shroeder that he did to him. He shoves Scully in the closet and fights with the creature. Meanwhile, Mulder confronts Gogolak about marking the Klines for death by giving them the tacky windmill. Mulder says the creature is a tulpa, a Tibetan thoughtform, that Gogolak conjured to assure compliance with the HOA rules. Gogolak is unconcerned, stating he could never prove that in court and Gogolak would ruin him in the process. Mulder arrests him anyway, handcuffs him to a post outside and finds Scully trapped in the closet inside, the room splattered with blood and broken furniture.
Gogolak begs for help, knowing the creature is coming. Shroeder starts toward Gogolak, but his wife stops him, stating Gogolak gets what he deserves. Mulder, still digging Scully out of the closet, hears screams outside and rushes out of the house. He sees the creature attack Gogolak and, as he dies, the creature disintegrates into dirt. Scully comes outside too late to see the creature, the remnants of which are at Mulder's feet.
The epilogue as narrated by Scully, stating the neighbors have now blamed Gogolak for the previous deaths, but claim ignorance as to how he did it or what killed him. The Falls at Arcadia remains one of the top planned communities in the US.
- SCULLY: Okay. 6:01 p.m., February 24. Agents Scully and Mulder in the former home of David and Nancy Kline who disappeared without a trace last July. The Klines were the third such couple to disappear since this neighborhood was built in 1991. All were apparently stable professional people with no history of violence, domestic discord or mental illness and it took a family member or employee to realize that they were gone including their cars and a few personal items. What local police found in each case was nothing—just impeccably-manicured homes and a community of neighbors who professed total ignorance that anyone had disappeared.
- MULDER: That's pretty surprising considering how nutty this bunch is about being neighborly.
- SCULLY: The local police departments were at a dead end so they turned to the FBI. AD Skinner, in assigning us this case thought a fruitful approach to the investigation would be if we went undercover posing as prospective home buyers as this planned community would seem to hide a dark, possibly murderous conspiracy of silence.
(MULDER comes very close into the video frame.)
- MULDER: (seductively) You want to make that honeymoon video now?
(SCULLY turns the camera off. MULDER sits on the kitchen counter and pulls his gloves off.)
- SCULLY: Rob and Laura Petrie?
- MULDER: "Pee-trie."
- SCULLY: Mulder, if we ever go undercover again I get to choose the names, okay?
- MULDER: Fine.
- SCULLY: It just tells me that you're not taking this seriously.
- MULDER: I'm taking it seriously. I just don't understand why we're on it. It's our first catch back on the X-Files. This isn't an X-File.
- SCULLY: Sure it is. It's unexplained. What do you want, aliens? Tractor beams?
- MULDER: Wow. Admit it: you just want to play house.
(Doorbell rings. SCULLY gives him a look and starts for the door.)
- MULDER: (demanding) Woman, get back in here and make me a sandwich!
(SCULLY stops, smiles slightly and snaps off her gloves and throws them at his head and continues on to the door.)
- MULDER: Did I not make myself clear?
- An episode inspired by the Kolchak: The Night Stalker episode, The Spanish Moss Murders, where a mythological Louisiana bayou creature is brought to actual life through a man's dreams.
- When Scully is doing her videoing, she mentions that Skinner had suggested they go undercover as 'prospective homebuyers'. Yet I don't know of any community - perfect or not - that allows 'prospective' buyers to move in with all their furniture and other bits and pieces. They even have the mailbox changed to show their names. And they certainly wouldn't be able to dig up the lawn for a reflection pool if they didn't own the property! Especially given the rule-heavy nature of this community. Reasoning: Every homeowner is prospective at some point. At the start of the assignment they would have needed to make the purchase so at that point they were indeed posing as prospective homeowners.
- The Ubermenscher is actually a Tulpa, a Tibetan thoughtform that is brought to life through mysticism.
- The Name 'Ubermenscher' is very close to the German word 'Übermensch', which means 'superhuman'.
- The name "Polizzi" painted on one of the neighborhood mailboxes is in honor to Lauren Polizzi, one of the art directors on The X-Files.
- When Mulder first discovers the hole in his neighbor's lawn and is lifting the grass, camera equipment is visible on the right side of the screen.
- When Scully starts filming she gives the date as February 24 but in the close-up shots of Mulder's watch the date is the 7th and then the 9th.
- In the previous episode, "Monday", a close-up shot of Mulder's watch showed days of the week, rather than days of the month.
- When Mulder lays on the bed while Scully is in the bathroom, he has his shoes on, but when Scully says goodnight to Mulder, he is wearing only socks, and his shoes are on the bed.
- The Dick Van Dyke Show: Mulder and Scully use the pseudonyms, Rob and Laura Petrie, while undercover on this job, which are the names of the main characters on The Dick Van Dyke Show.
- Episode Title: Arcadia
In ancient Greece, Arcadia was the name of a district famous for its rustic peace and simplicity.
- Movie: The Colony This episode is reminiscent of the 1995 movie The Colony starring John Ritter. The premise of the movie is about a secluded, planned community with outrageous rules and regulations which hides a dark underbelly where the so-called 'safe and secure' feature involves hidden cameras throughout the homes, and several residents are killed because of their knowledge of this; similar in the way that the residents of 'The Falls' are killed for not following the rules.
- Peter White as Gene Gogolak
- Abraham Benrubi as Mike Raskub
- Debra Christofferson as Pat Verlander
- Tom Gallop as Win Shroeder
- Marnie McPhail as Cami Shroeder
- Roger Morrissey as Ubermenscher