During a New Year's visit to her husband Chester's family home, Selma is warmly greeted by his childhood friend Shirley, who insists on cooking for her. Shirley, having already been told Selma is allergic to scallions, later reveals she has ground them into the soup. In a flashback, Selma recalls her past life where this act landed her in the hospital, with Chester's family dismissing her concerns. Now, as Shirley questions Selma's sudden claim of a ginger allergy, Selma deliberately alters her request, setting a trap to expose the family's hypocrisy and begin her revenge.