Edina is none too pleased about her 40th birthday. As opposed to the glamorous, star-studded surprise party she had hoped for, Edina is disappointed to learn that Saffron has planned a quiet lunch with family and friends—including both of Edina's ex-husbands, Justin and Marshall, and their respective new lovers, Oliver and Bo, as well as Patsy and Mother. Edina behaves erratically during the party, switching between self-pity and spite, and she soon provokes Oliver, her least favourite guest, into making an angry exit. Justin and Marshall are shocked to discover that they have both been paying alimony to Edina. While Edina and Patsy sing drunkenly on a new karaoke machine, Justin and Bo secretly plot to cut off Edina's alimony.

Patsy accidentally burns down the Monsoons' kitchen with a cigarette. She and Edina later plan a night out, but they decide to stick around after learning that Saffron is expecting a date, much to her chagrin. To make matters worse, Mother inadvertently locks the three women in the living room on her way to the chemist's. Edina pesters a mortified Saffron with questions about her sex life, before the trio exchange stories about their own births. Patsy—who had a neglectful mother—expresses her resentment towards Saffron due to the privileges she enjoyed while growing up, leading to a bitter dispute between the two. When Mother eventually returns home and unlocks the door, Edina and Patsy quickly leave, while Saffron's date is waiting outside. A flashback sequence shows Edina as she plans to surrender Saffron for adoption.

For the first time ever, Edina has agreed to stay home and spend Christmas with the family. Edina typically goes overboard by buying a huge tree and tons of gifts. Patsy is very upset that she cannot go away on vacation with Edina as they do every year, as she hates Christmas. Patsy has a flashback of unpleasant Christmas memories of her childhood. Someone somewhere sticks a pin in a Patsy voodoo doll, and she collapses in pain beneath the Christmas tree. Although Edina and Saffron ignore her, John insists that Patsy needs to go to the hospital. Once at the hospital, the doctors tell Edina that Patsy is very sick and that she may die. Edina and Saffron return to the house to continue their Christmas celebration. In the middle of the night, Patsy's estranged sister Jackie arrives to visit her. The following day, Edina and Saffron drop by only to learn from a nurse that Patsy has died, only they find out that it turns out to be Jackie instead.