Another one of the Brooks brood come visiting when Herman's little sister Suzie arrives in New York. Already over-protective of Suzie, Herman's anxieties get even worse when she and Jay sleep together.

Herman's sister Suzie comes back to town and manages to aggravate both Herman (she plans to become a writer) and Louise (since she previously dated Jay). Appropriately, the ""brain"" characters get a new and annoying addition when Jealousy joins their group.