After watching Barb charm a city councilman at a historic preservation event, Bill begins to see his wife through new eyes. A spontaneous roadside rendezvous re-ignites their sex life, and soon the two are sneaking off for clandestine trysts in a hotel.
Nicki begins to suspect Bill is having an affair - and planning to bring in a fourth wife. She can't wait to be the one to tell Barb. "First wives think they know everything," she tells Joey's wife, Wanda, "but really they just walk around in a fog." For her part, Nicki is "so excited" for a fourth, especially as she's become "really bored with Barb and Margie."
Using a false name, Don calls the Attorney General's "polygamy czar" and tells him his mother was swindled by Roman's desert ranch scam, as Bill offers cues in the background. The man asks Don to bring his mother down to the office and file a statement. "We've been trying to get into Juniper Creek forever," the man says. "Maybe we could piggyback an investigation." Don tells him he'll work on it.
Bill's bookkeeper, Wendy, has a tip of her own; she pulls Bill aside to inform him that she saw Don with several women at an Appleby's, and after following two of them into the women's bathroom, she's certain they're polygamists. "It's against the Church and the law," she declares. Bill tries to assure her Don is "not what you are saying he is," and besides, "everyone in the Henrickson Home Plus family is treated with respect." But Wendy isn't ready to put it aside. She confronts Peg Embry in the Home Plus bathroom. "I've got my eye on you," she tells her, "you can't fire me or get me fired for doing and saying what I know is right." Peg smiles graciously. "Why would I want to go and do something like that? You're the best little junior bookkeeper we've ever had."
After a Juniper Creek manager reviews Alby's audit of the Home Plus books, Roman is disgusted with his son for delivering only a digest of numbers. "He's no genius," he says to the manager, as Alby looks on. Later, when Alby tries to apologize and fix his error, Roman dismisses him further. "It's not your fault... our talents lie elsewhere... You let Bill get the better of us."
Overhearing the exchange, Rhonda offers Alby a ride home. "I can't do numbers, either," she says, sympathetically. At this Alby finally erupts. "SHUT UP!" he screams at his father's teenaged bride-to-be. The brazen Rhonda snaps back: "Don't you ever raise your voice to me like that again."
With Barb back to teaching and Nicki's ongoing hostility, Margene's been feeling lonely. So when the new neighbor Pam strikes up a friendship, she's thrilled, going so far as to invite the woman into her house. Sick of strangers thinking she's an unwed mother, she tells Pam that she's a widow, and that her husband died in the Gulf War. Later, when Pam relays her sympathy for 'the widow' to Barb, Barb confronts Margene about her lack of discretion - they have to be extra careful now that there's a second store. And besides, she reminds her, the Gulf War was 15 years ago.
Nicki adds her two cents to the scolding: "You're the weak link Margie...You can't keep a secret like me and you are not a good liar like Barb." Barb is ultimately a little more sympathetic; she lets Margie know she understands how isolating their lives can be. But she tells her they "have to stick with it no matter how lonely it can be, because there isn't anything else that can bring these rewards."
Tortured by wet dreams and a preoccupation with sex, Ben has decided to attend Mormon seminary after school. "I don't feel pure," he explains to his girlfriend Brynn. "I think there's something inside me that shouldn't be there." Brynn assures him that thinking about sex is a good thing, and that seminary will only brainwash him into believing there's something dirty about his body. Besides, she's worried that he'll become "judgmental and arrogant" like the other Mormon boys she's dated. "Don't let them ruin you," she urges him.
When she discovers a hotel soap wrapper in her bathroom wastebasket, Nicki is beside herself. She confronts Margie about whether she and Bill had pre-marital sex, then corners Barb. "I'm not sure Bill wants you to know, actually," she tells her, "Bill is dating someone...a fourth wife." Barb seems baffled by the news - and by Nicki's certainty. But Nicki insists they confront Bill and find out "who is bringing the sin into our house."
Joey helps Bill by digging up the contact information for the attorney suing Roman for the land scam. He also congratulates his older brother - he learned from Wanda that he's planning on taking on a fourth wife. Bill is dumbstruck. He's barely interested in taking on more than one these days.
After dinner a few days later, Bill tells Nicki he has to go in to the office. She presses the redial button on her phone to reveal his last call: Sarah picks up, explaining her mother just left. Watching Barb's car head in the same direction as Bill's, Nicki starts to put the pieces together.
While Barb and Bill are at the hotel, an ominous man appears in the back porch of Barb's house, scaring Tancy half to death. Nicki heads outside to confront the intruder and discovers an angry Alby, with attendants, demanding to see Bill. When Ben comes to the door, Alby grabs him by the neck. Nicki manages to pull him away. "I'll have Papa come down on you like a ton of bricks!" Alby scoffs at his younger sister. "You? You were a nothing until you married Bill... Bill took you to get a loan from Papa. Don't you know that? You're just collateral."
Barely containing her fury, Nicki figures out a way to get even. "Take your one testicle and fly back to your cave," she tells him, adrenaline rising. "You ever show up here again and harass this family again, I swear to God I'll kill you!" With witnesses present, Alby retreats.
Later that night, Nicki gathers the family around her living room to deliver some news: she's ready to bring another soul into the family. "We've been holding off, for this reason or that. It is time now. We've let worldly concerns come before what we're here for. What our purpose is." The family exchanges glances as Bill embraces Nicki. "I'm so happy, as your husband, father to be, and member of our holy family," he tells her. Looking confused and suspicious, Margene offers her congratulations. Barb recovers quickly from her shock. "I love you Nicki," she says, smiling warmly. "I love you too, Barb. I love you very much."