In the series finale, Betty is anxious about telling Daniel her future plans; Justin and Bobby try to convince Hilda that they should move to Manhattan; Amanda mourns the loss of a loved one; and Marc is discouraged by his romantic prospects.
The approach of Hilda's wedding presents RSVP choices for Betty, Ignacio and Marc. Meanwhile, Justin considers his friendship with Austin; Betty mulls a professional change; and Wilhelmina recruits an unwitting ally in her war against the Meades.
Amanda and Hilda join Betty on a trip to Fashion Week in London, where Betty reconnects with Christina (Ashley Jensen) and has a chance encounter with Gio (Freddy Rodriguez). Meanwhile, Wilhelmina goes to extremes to undermine Claire and Daniel by getting close to Tyler, and Bobby wonders why Justin and a classmate have become inseparable.
Before Betty's new orthodontist (Kathy Najimy) removes her braces, she gets knocked unconscious at a photo shoot and takes a dream-like look at an alternate universe in which she never wore them at all. But with an upside-down family and a kindred spirit in Wilhelmina, it's not a pretty picture.
The love bug bites twice at Justin's acting school when he's attracted to a classmate, and then his Aunt Betty falls for a playwright she's writing about for Mode. Meanwhile, Wilhelmina lands in the hospital with a perforated ulcer. Carol Kane guest stars as Justin's teacher.
Betty reluctantly dates an irritating firefighter (Rich Sommer) to help the investigation of the recent blaze at the Suarez house. Meanwhile, Hilda meets Bobby's parents (Lainie Kazan, Nestor Serrano); Wilhelmina accentuates her humble roots when she runs into an old boyfriend (Brian Stokes Mitchell); and Claire considers a position at Mode for Tyler.
Despite Wilhelmina's slight during New York's Fashion Week, Betty tries to make the most of an opportunity when she pegs a new designer as one to watch. Meanwhile, Claire's son Tyler (Neal Bledsoe) comes looking for her; Amanda finds an unlikely business partner; and a fire breaks out at the Suarez house. Designer Brian Reyes appears as himself.
Betty's blog wins an award, but her online unloading risks driving a wedge between her and Daniel when the press gets a whiff of the tension. Meanwhile, Wilhelmina is beside herself when she learns she has a drag-queen impersonator; Amanda gives Helen another chance at Mode; and Marc oversees a photo shoot with a well-known director.
Betty plans a karaoke party for her fellow tenants, but her efforts to be a good neighbor go for naught after the apartment building is robbed. Meanwhile, Amanda intervenes when Daniel and Wilhelmina resume their heated rivalry; Ignacio has a difficult time making peace with Bobby; and New York City is plagued by a massive power outage.
Betty vents to Mr. Z (Fisher Stevens) about the rotten week she just had, which included a series of ridiculous tasks from Wilhelmina. Meanwhile, Daniel has a strong suspicion that Marc is undermining his authority; Bobby tries to stay on Hilda's good side; and Wilhelmina makes a promise to Connor.
Betty surprises Matt with a gallery exhibit of his art when she feels they're in danger of becoming inseparable; Marc is haunted by a Bahamas fling; Hilda ponders telling Bobby about her pregnancy. Christine Ebersole guest stars as a gallery owner.
Ignacio's preparations for a holiday feast with his new girlfriend, who's Jewish, coincide with Hilda and Betty worrying that the Suarez family is about to have two new members. Meanwhile, Cal hires a movie mogul (Nadia Dajani) to replace Wilhelmina as Mode's creative director, and Amanda helps Claire search for the son she gave up for adoption.
Love is in the air when a photo shoot takes the Mode staffers to resort in the Bahamas (where singer Shakira is a guest), but the job also creates friction between Wilhelmina and a rival editor (Christie Brinkley). Meanwhile, back in Queens, Hilda reconnects with an old flame (Adam Rodriguez). Matt Newton, whose sister Becki plays Amanda, also guest stars.
When Daniel gives Bennett (Dylan Baker) and the Community of the Phoenix unprecedented access to the levers of power at Mode, Betty hatches a plan to shock him back to reality. Meanwhile, Wilhelmina uncharacteristically stops caring about her appearance, sending Marc on a quest to find out more about Nico's story. Natalie: Jamie-Lynn Sigler.
A teacher (Adam Rodriguez) at Justin's school sends Hilda and Betty swooning down memory lane; Daniel takes Amanda to a meeting of his support group; Marc points Justin in a new direction in his search for friends at school; Wilhelmina goes to extremes to help Nico.
Betty feels left out when Daniel makes Natalie (Jamie-Lynn Sigler) his new assistant; Wilhelmina's fund-raiser for Tibetan orphans creates a dilemma for Matt; Claire's history with Cal is revealed to her son.
Marc is assigned to be Betty's temporary assistant while she works on a story about New York's worst jobs; Hilda becomes a potential political liability to Archie's campaign; Natalie's group leader (Dylan Baker) takes an interest in Daniel. Lexie: Brooklyn Decker.
One of Hilda's customers (Adam Ferrara) helps Betty get scoop from a top designer, but when Marc plots against her, it leads to a confrontation at the restaurant where Ignacio works. Meanwhile, Daniel meets an exciting woman (Jamie-Lynn Sigler) at his support group, and Wilhelmina searches for Connor in the Caribbean.
Conclusion. Betty's allegiance to her old boss threatens to undermine her responsibilities at a photo shoot at the United Nations; Amanda gets a glimpse of her future when she meets Daniel's new assistant; Hilda needs help getting through to Justin about his troubles at school; Wilhelmina's maternal instincts kick in during a personal crisis.
In Part 1 of the two-part fourth-season premiere, Betty settles into her new job as an associate editor at Mode but clashes with her ex-boyfriend Matt, who's now her boss, and tries to stay a step ahead of Marc, who feels slighted by her promotion. Meanwhile, Daniel struggles to cope with Molly's death and the loss of Betty as his assistant, and Justin has trouble fitting in at high school. Lynn Redgrave guest stars.