Sterling Cooper works with a client whose dog food has been discovered to be horse meat. After several elaborate arguments, they convince the client that the only way to sell the product is re-brand. Greg fails as a surgeon. His first interview for a psychiatry job goes badly. When Greg tells Joan that if he cannot be a surgeon, he really wants nothing, she tires of his self-pity and hits him over the head with a vase. So he pursues a career as an army surgeon. Betty confronts Don with information she found from his past, and he tells her all of his secrets. Don then breaks off his relationship with Suzanne.
That night it's Halloween, and Don and Betty take Sally, Bobby and Gene trick-or-treating. "Look at this, we've got a gypsy and a hobo," observes the father who answers their first doorbell. He then looks at Betty and Don. "And who are you supposed to be?"
This episode contains examples of the following tropes.
- Asshole Victim: Greg would get little sympathy from fans because of what he did to Joan in the past.
- Brutal Honesty: When Annabelle tells Roger she wanted him after her husband died, and that he was the one, Roger simply replies, "You weren't."
- Continuity Nod: Don describes what happened to his brother Adam.
- Dark Secret: Betty tells her lawyer this about what she learned of Don's past: "Its a lie so big, I feel like I've been in a dream."
- Get A Hold Of Yourself Man: Joan hits Greg on the head with a vase, and he doesn't retaliate.
- Misplaced Retribution: Caldecott Farms has been revealed in an expose as using horse meat to make dog food. No one will buy their products anymore, instead turning to other brands... which, like all dog food at the time, are also made of horse meat, they just haven't had the misfortune of having their operations publicized. (This is fundamentally why Don wants to change the brand's name: it's not just that Annabelle won't change the product, it's that there's no changes that could be made.)
- Not Actually the Ultimate Question: After Don has confessed his Dark Secret to Betty, they take Sally and Bobby trick-or-treating, and after the neighbor comments on the kids' costumes (see Title Drop below), he asks Don, "And who are you supposed to be?"
- Shout-Out: When Annabelle is having dinner with Roger, she tries to compare their previous relationship with Casablanca; Roger retorts it was nothing like Casablanca.
- Later, after dinner is over, Annabelle talks about meeting Hemingway.
- Slap-Slap-Kiss: Joan and Greg have this kind of relationship.
- Son of a Whore: Don describes his childhood as one of these.
- The Story Teller: Betty tells Don that he's a very good one of these.
- Sudden Name Change: This is the major theme of this episode. The name of dog food must be changed. Likewise, Don had suddenly changed his name to escape from Korea.
- Title Drop: For Halloween, Sally is dressed as a gypsy and Bobby is dressed as a hobo.
