Betty and the kids are preparing to leave town for a week. She asks Don for some additional cash. He tells her to swing by the bank. "You have no more money?" Betty asks. Don pecks her on the cheek without responding.
Roger, Don, and Cooper meet with Annabelle Mathis - an old flame of Roger's. Annabel's company, Caldecott Farms, is losing market share because consumers have learned its dog food contains horse meat. She's challenging the big ad agencies to reverse public opinion. The ground rules: She won't change the recipe, or the product's name.
"What are you doing here?" Roger later asks Annabelle, a recent widow. Her business needs help, she explains, and she wanted to see him. The two arrange to have dinner.
At her apartment that night, Suzanne laments that she and Don can't dine in public, but then backpedals: "I swear, I'm not talking about our future," she says, though she adds that whether she pictures herself in Don's life or not, she sees an unhappy man. "I'm happy now," he replies.
Joan coaches Greg for a psychiatry residency interview. He reveals a family secret -- that his father underwent psychiatric treatment -- and she encourages him to be as open with the interviewer as he was with her.
"I just wanted more than I thought I would want," Suzanne tells Don that night. "But it'll pass." Don says that he doesn't want it to. With Betty out of town, Don proposes that he and Suzanne go away somewhere. She agrees.
Joan calls Roger for help finding work. "I like that you thought of me," he says.
At Gene's house with their father's lawyer, Milton, William and Betty discuss selling the property. "This is ugly," William declares when told that his proposal to purchase Betty's share at a discount violates the terms of Gene's will.
Betty, seeking Milton's advice in private, describes Don's secret past. Divorce could leave her broke, Milton explains, and she could lose custody of the children. "It's a lie so big," Betty argues. After getting her to agree that Don is a good provider and wouldn't harm her, Milton counsels Betty to try to salvage her marriage.
Over dinner, Annabelle reminisces about being young and in Paris with Roger, who reminds her that she dumped him for someone her father found more suitable. Roger, she counters, was adrift, walking around "like you were hoping to be a character in somebody else's novel." The two drink heavily, but when Annabelle says that she knows Roger still wants her, he replies, "So what? I'm married," and sends her away.
At their apartment, Greg sulks to Joan because his interview went poorly. Referring to his surgery career, he says that she doesn't know what it's like "to want something your whole life" and not get it. Joan bashes his head with a vase.
Annabelle watches behind a two-way mirror as focus-group participants become incensed when told their pets are eating samples of Caldecott Farms dog food. "The name has been poisoned," Don says. She will find another agency to solve her problem, she declares.
"Is this about last night?" Roger asks Annabelle later. He concedes that she broke his heart years ago. "Well it was a mistake," she says. "You were the one." "You weren't," he replies softly.
Suzanne remains in the car when Don stops at his house before their trip. Discovering that Betty and the kids have returned early, he says that he left his hat in the car. "Get it later," says Betty.
Betty orders Don to open his desk drawer. He refuses. "You know I know what's in there," she says, opening the drawer.
Unsteady, Don says that he needs a drink. Regaining some of his composure, he asks quietly, "Where do you want me to start?"
Don explains how he assumed the real Donald Draper's identity following an accident during the Korean War. "I found out it was easier to be him than to start over," he says.
"Why couldn't you tell me any of this?" asks Betty after Don recounts the details of his marriage to Anna Draper. "When?" he says. "The day we met? On our first date? On our wedding night? Why did you need to know?"
"What would you do if you were me? Would you love you?" Betty asks. Don says that he was surprised that she ever loved him. "I don't know who you are," Betty says. "Yes you do," Don replies.
Looking at photos, Don tells Betty about his prostitute mother; his father, Archibald Whitman; and Archibald's wife, Abigail, who raised him. Don sobs over his half-brother Adam's suicide. "I turned him away," he says. "He just wanted to be part of my life and I couldn't risk all of this."
Roger, meanwhile, phones a friend, suggesting that Joan could whip his business into shape. "She's important to me," Roger says.
Over at Joan's apartment, Greg returns with flowers, an apology for "feeling sorry for myself," and a surprise announcement: He's joined the army. He'll be able to work as a surgeon, and Joan won't have to return to work.
Outside Don's house, Suzanne exits the car and walks away.
Don calls Suzanne from his office the next morning to say that he can't see her anymore. "Are you okay?" she asks. "Only you would ask about me right now," he says.
That evening Don and Betty take the kids trick-or-treating. "Look at this," says Carlton, Francine's husband, to Sally and Bobby. "We've got a gypsy and a hobo." Glancing up at Don, he asks, "And who are you supposed to be?"