Teaser: In a nice, normal-looking neighborhood in Kansas City, Kansas, two young missionaries on bicycles visit the home of Betty Templeton. We see her car, a red convertible with a personalized Missouri plate reading "BETTY" and two bumper stickers: "Eat Right, Exercise  Die Anyway," and "Cleverly Disguised as a Responsible Adult." At the door, Betty Templeton, a plain-looking woman with long, curly red hair, says she's not interested in the missionaries' message, adding that she's just moved in.

The missionaries ride on to another house, featuring a blue convertible, with a personalized Arkansas plate reading "LULU," and bumper stickers: "Eat Right, Exercise  Die Anyway," and "Cleverly Disguised as a Responsible Adult," the positions reversed from the other car. The door is answered by Lulu Pfeiffer -- who looks just like Betty. The missionaries are surprised at the resemblance; Lulu appears shaken when they comment on it, and slams the door in their faces.

Outside, the missionaries look at each other and begin a shoving match that rapidly degenerates into a fistfight on the front lawn. A police car shows up, and the missionaries even try to fight them.
 

The next day, a tall, dark-haired man and a short, red-haired woman, both in suits, approach Betty's door. She is shown, not them. The man, who sounds like Mulder, says they're with the FBI and are investigating a possible hate crime in the area. Betty says she doesn't know anyone, and the woman, who sounds like Scully, says they have two men in their car who say otherwise. It's the two missionaries, in bad shape. Betty asks what happened, and the man says the missionaries beat each other up after visiting a woman who looked just like Betty. The man begins asking if Betty practices the occult or such things as "the black art of bodily bilocation"; she replies that "everyone has a twin out there somewhere."

The man and woman look at each other -- they're not Mulder and Scully. But they look a lot like them. [Note: They are, in fact, their stand-ins.]

The woman who looks like Scully tells Betty that the other house is empty. Just then, the blue convertible, driven by Lulu, comes by, followed by a moving truck. The three watch as it passes, and Lulu and Betty look at each other, hostiley. Pseudo-Mulder and Pseudo-Scully look at each other, and she punches him. He hits back, and they start fighting. Betty slips into the house, and she and the missionaries watch as the FBI agents beat each other to a pulp. Pseudo-Scully breaks away and runs for the car; pseudo-Mulder goes after her, grabbing her through the window. She drives away, and we hear the sound of screeching tires and a crash.
 

Mulder's office. He's showing slides of the FBI agents and what happened to them. He suggests several possible explanations in a manner indicating he doesn't think that's what happens at all. He also mentions that the agents have been partnered for seven years but "are not romantically involved, if that's what you're thinking." Scully (a bit sarcastically): "Not even I would be so farfetched."

Scully says the situation is so familiar -- "Playing Watson to your Sherlock. You dangling clues out in front of me one by one.  It's a game, and... and, as usual, you're, you're holding something back from me.  You're not telling me something about this case."

Mulder "hmmms" noncommitally in response, so Scully starts throwing out ideas, Mulder responding with various sounds and gestures, until she finally hits on something -- a doppelganger. He taps his nose; she got it. And then she proceeds to impress him with her definition: "A corporeal likeness that appears unbidden from the spirit world the sight of which presages one's own death or... a double, conjured into the world by a technique called bilocation, which in psychological terms represents the person's secret desires and impulses committing acts that the, uh, real person cannot commit himself -- or herself?"

Mulder smiles in response, to which Scully demands the next slide. It's Betty's driver's license.

Scully: "Yes!"

Mulder: "Don't go thinking I'm going to start doing the autopsies."
 

Downtown Kansas City. Lulu enters a Koko's Copy Center and asks about a sales job she applied for. The manager says there's a problem with her application -- she moves a lot, and she's had 17 jobs in 17 states in the past three years. She says she has "a restless streak." The manager continues to pick apart her history, but suddenly all the copiers start acting up. Desperate, the manager says she can start right then.

Lulu's happy, but then Betty's convertible pulls up outside. She checks the want ads in her paper, but then the manager removes the help wanted sign in the window. Disappointed, Betty drives away.

At a different Koko's, Betty has a conversation with the manager there that sounds very much like the one Lulu had. Betty also has had 17 jobs in three years, but she tells the manager "I'm here in Kansas City to stay."
 

Porcherir Hotel, Kansas City, Kansas. Bert Zupanic sits in his room, counting money into a briefcase, when someone knocks at the door. It's Mulder; Zupanic hides the money and answers the door. Mulder and Scully question him about Betty Templeton, but Zupanic says he doesn't know her -- even though Scully shows a newspaper picture of Zupanic with a woman who looks exactly like Betty. Lulu, perhaps? Zupanic is either confused or evasive, or both, and Mulder and Scully leave.

In the hallway, Mulder asks, "You know what I'm thinking?" Scully replies, "That Mr. Zupanic not only knows Betty Templeton and where we can find her but that he is hip [??] to whatever she's into and that I should look at that house on Moreton Bay Street while you go and find out from Mr. Zupanic what it is exactly that he's clearly hiding about Betty Templeton."

Mulder: "I'm thinking that Bert Zupanic really truly doesn't know Betty Templeton."

Scully: "Well, I guess that's why they put the 'I' in the FBI."

As Scully leaves in the elevator, Mulder looks down the hall, hides as Zupanic leaves, then goes back to the apartment.
 

Froggy's Bar. Zupanic enters, carrying the suitcase, and asks the bartender for a double. The bartender replies, "I thought you were in training, Bert my man," but Zupanic shoots back, "Would you just pour?"

Zupanic sits down next to Betty Templeton, who's sitting at the bar, still in her Koko's uniform. He orders a drink for her; Betty's not only inebriated but surprised that Zupanic knows what she drinks. Zupanic's taken aback at her reaction and takes the drink out of her hand, telling her maybe she's had enough.

Zupanic: "You are in trouble, aren't you?"

Betty: "I don't know. I could be. What kind of trouble you looking for?"

She introduces herself, and Zupanic laughs. Betty looks up to see Lulu entering the bar. The two women glare at each other; the bar starts to shake, and the glasses and bottles start exploding. Lulu leaves, and it all stops.
 

Pat Devine's, Kansas City Auditorium. Scully enters and hears two men talking and laughing, then Mulder calling her. She spies him sitting next to an older black man, Argyle Saperstein. Scully approaches, and Mulder introduces Scully to Saperstein -- mispronouncing the man's name in the process. Scully is not amused.

Scully: "So I take it from your posture, Mulder, you solved this case."

Mulder says no, but that he has narrowed things down. Zupanic is a semi-pro wrestler, and according to Saperstein, Zupanic is involved with the "mystery woman."

Saperstein: "If it's the lady I'm thinking, she's not much to look at, but he says she brings him luck."

Scully asks if they're supposed to just hang around in Kansas City until the woman shows up. Mulder replies that there's plenty to do in town, "Plus Mr. Saperstein's going to show me some in-your-face, smack-down moves so I can quit getting my ass kicked so often, right? Oh, and there's an art exhibit that traces the influence of Soviet art on the American pop culture, right?  Unless, of course you've already found Betty Templeton."

Scully replies that finding Betty won't solve the case unless they also find Lulu Pfeiffer. Mulder asks who that is, and Scully tells him she's the doppleganger, but a real one, "not a manifestation." She says the two women appear unconnected, but they've followed each other across 17 states for 12 years, "and wherever they have been, mayhem has followed." Not small stuff, either, she says. Saperstein is impressed.

Mulder and Scully leave, and Saperstein dials his cell phone. The phone at Zupanic's rings, and the wrestler is in bed with Betty Templeton. He answers, and Saperstein demands his money; Zupanic says he's got it, and Saperstein tells him "the feds" are looking for him. Saperstein tells Zupanic to bring the money to Froggy's or there'll be no fight.

Betty asks if Zupanic is in trouble and he's evasive. Betty sees the time and says she's going to be late for work; she jumps up and grabs her uniform, then pauses to kiss Zupanic and compliment his performance.

As she disappears into the bathroom, someone knocks at the front door. Zupanic opens it to face Lulu, in her uniform. He's stunned. She asks where he was, accusing him of two-timing her, but he denies it, saying she's his good luck charm. Lulu is crying and yelling and looks under the bed, then finds a hairclip in the bed and says it's hers. She's suddenly affectionate and hugs him, apologizing. She leaves, and Betty comes out of the bathroom. A loud argument starts in the room upstairs, and then gunshots are fired. Zupanic and Betty are surprised as bullet holes appear in the ceiling.
 

Froggy's Bar. The bar is back in shape, glasses stacked, and Saperstein is at the bar, eating. Betty comes in, in uniform, and Saperstein asks, "Where's 'The Titanic'?" Betty's confused, then happy to find out Zupanic will be there. She heads for the bathroom to "freshen up."

Zupanic enters with the suitcase and sits next to Saperstein, who says he just talked to Zupanic's girlfriend. The bar rumbles, then stops, and Lulu walks in, wearing her uniform. Saperstein stares; "how did she do that?" He tells Zupanic he just saw her going toward the bathroom.

Zupanic goes to Lulu and tries to escort her out, telling her he has a business meeting. She says she just wanted lunch, and he tells her he'll bring it out to the park and they can have a picnic. She leaves, and as Zupanic gets back to the bar, Betty comes out of the bathroom and sees him. The rumbling starts back up and Lulu comes back in, starting to tell Zupanic she only has an hour for lunch.

The two women see each other and stare. The rumbling builds, and the bar explodes again, glass shattering. Zupanic is hit and knocked to the floor, and Betty and Lulu leave through different exits. Saperstein takes the briefcase and leaves.

Later, Mulder and Scully are there, and people are cleaning up. Scully is checking Zupanic's pulse as he wakes up and asks what happened. Scully tells him he was struck my flying glass. He starts looking around, and Mulder asks if he lost something.

Zupanic: "Yeah. My good luck."

Scully: "Would that be Betty or Lulu, Mr. Zupanic?"

He looks at her, and she says the woman are the ones who caused the mayhem and that they'll do it again. She asks where they are.
 

Koko's, the one where Betty works. Mulder enters and finds the manager, showing his badge and asking to talk to Betty. Betty tries to put him off, then blames Lulu for everything.

Betty: "She follows me around trying to ruin my life. I'm not going to let her ruin it this time. It's either me or her. I don't want to leave Kansas."

She leaves. Mulder follows her outside, taking out and dialing his phone as he walks. He talks to Scully, saying he found Betty; Scully is at the other Koko's, watching Lulu drive away. Scully says Lulu said the exact same things Betty did.

Scully: "What's going on here?"

Mulder: "I don't know, Scully. You're running this show. Why don't you tell me?"

Scully theorizes that it's more than just physical proximity; that the women have "some kind of a psychic connection." Mulder, distracted, asks were Lulu is, and Scully tells him she left. He asks if she's driving a blue convertible, and Scully confirms it.

As she answers, Lulu pulls up on the opposite side of the street from Betty; Mulder is now standing between the two cars. The two women stare at each other. Mulder realizes what's coming and says, "Oh, crap." The ground starts rumbling, a manhole cover flies up, and Mulder falls to the ground. He's pulled into the manhole, feet first, and the cover slams back down.

The two women pull away, in opposite directions.

Some time later, Scully shows up and looks around for Mulder -- while standing on the manhole where he disappeared. She goes inside and asks the manager, who says Mulder left and he didn't know where. Scully asks if they have internet access.
 

Kansas City Penetentiary. A guard escorts Scully to a cell, and she asks him to wake up the man inside. He's reluctant, but he's saved the trouble when the man in question starts yelling at them to "shut up or go away." Scully approaches the call and is faced with Bob Danfous, who's irate and screaming at her. Scully gets more icily polite every time he yells, telling him that she's discovered his donation to a sperm bank may have resulted in him fathering two daughters -- Betty and Lulu. She wants information about his family, but he's not helpful in the least.
 

Zupanic's room. Betty knocks on the door, twice, and Zupanic finally answers. He tells her the fight that night is his last shot at the big time and he needs her help to get the money for the fight. She says maybe she can help, kisses him, and leaves. Zupanic sits back down, but a few minutes later, Lulu knocks. Apparently covering all his bases, he starts telling her about his "big trouble."

At Koko's, Betty breaks in and starts running high-quality copies of hundred-dollar bills. Lulu is doing the same thing.

At the still-smoking manhole cover in front of Betty's Koko's, the cover moves aside and Mulder pulls himself out, looking worse for the wear.
 

Kansas City Penetentiary. Scully is sitting at a table, doing more research, when her phone rings. She answers, "Mulder?" He says, "Yeah," and she asks where he's been. He replies: "Seeing a side of Kansas City few men have the privilege to see."

He asks about Betty and Lulu, and Scully fills him in on the results of her research, telling him she found the women's father and he's "probably the angriest man in the world."

Mulder:  "Not as angry as those two women are going to be when they both realize they're in love with the one and only Bert Zupanic."

Scully: "They're both after him?"

Mulder: "Yeah, they're both in love with him. That's why they're staying in Kansas City and they won't leave."

Scully says that still doesn't explain what's causing the problems or how to stop it. Mulder again throws things back to her, saying, "You're the one who's supposed to have all the answers. Somebody's got to get to that fight and keep those two women apart or else this time the [static] is going to hit the fans."

Scully has walked into a different cellblock as they've been talking, and an inmate says to her, seductively, "Well, hi." She stares at him as she hangs up; he looks exactly like Bert Zupanic.
 

Kansas City Auditorium. The main event is about to start, and the place is packed. Two men are wrestling in the ring; Zupanic, in a red wrestling costume, walks up the stairs, dejected. Saperstein approaches him and demands the money, threatening to cancel the fight. Zupanic is trying to say he'll have the money, when Betty comes running up the stairs carrying a Koko's bag full of money. Zupanic hands it off to Saperstein, who says, "Let's get ready to rumble."

Sapertein heads for the ring, and Betty and Zupanic hug. The match ends, and Zupanic's opponent, obviously the "bad guy, enters the ring. Zupanic climbs in and they talk some trash, then push and shove a little. Zupanic waves to Betty, and the fight starts. The men wrestle, Betty cheering Zupanic on loudly. Mulder enters the arena and approaches Betty.

Mulder: "Betty Templeton.  My name is Fox Mulder.  I'm with the FBI.  Can you come with me?

Betty: "I'm watching the fight."

Mulder: "Don't make me have to remove you, ma'am."

Betty sees someone behind Mulder; Mulder turns to see Lulu entering. The two women confront each other, arguing over Zupanic; Mulder looks at them, then picks Betty up over his shoulder and starts carrying her away. She keeps yelling at Lulu, then grabs a post on the ring as they pass and calls up to Zupanic, telling him she loves him as Mulder pulls her away. Lulu runs up and shows her bag of copied money, which Saperstein takes off her hands.

Suddenly fights start breaking out in the crowd. Mulder finally gets Betty away, but she keeps calling to Zupanic. The crowd fights more, as the wrestling match continues. Mulder stops and sets Betty down when he sees Scully enter with the Zupanic twin in handcuffs, a prison guard escorting him. Betty stares at the man, and Lulu walks up behind her, also staring. The fights stop, including the wrestling match, and Scully smiles at Mulder.

Then the two Zupanics see each other, and the one in the ring moves to attack the other, who pushes aside the guard to get at Zupanic. Mulder and Scully look at each other, alarmed, as all hell breaks loose in the arena.
 

Mulder's office. Scully's showing slides -- mug shots of the two Zupanics, shots of them fighting in the arena, then mug shots of Betty and Lulu and shots of them fighting. Saperstein is in the office, though neither he nor Scully is seen. Scully explains that both the twin Zupanics and Betty and Lulu are the results of anonymous sperm bank donations -- "non-fraternal biological siblings" -- who not only turned out very much alike but also chanced to meet, against all odds. Saperstein wonders what it means.

Scully: "I've been thinking hard about that, Mr. Saperstein. I would like to say it has something to do with balance in the universe, the attraction of opposites and the repulsion of equivalents, or that over time, nature produces only so many originals that when two original copies meet that the result is often unpredictable."

Mulder walks by, seen from the neck down, to a chair near where Scully's sitting. Her face is bruised and cut, with stiches in her cheek.

Scully: "If four should meet, the result is ... well, suffice to say it's better just to avoid these encounters altogether and at all costs.  I think Agent Mulder would agree with me.

She looks at Mulder, whose face is in even worse shape. His jaw is wired shut, so he does the only thing he can and moans out an agreeable sound through all the wire.