On slug days Lauren feels slow and slimy. She feels like everyone yells at her, and that she has no friends. Today there is a different bus driver; Dan and Sachi are sitting in Lauren's seat on the bus; and Lauren's teacher interrupts her reading time. It is definitely a slug day. But not every day is like this. On butterfly days Lauren makes her classmates laugh, or goes to get ice cream, or works on a special project with Mom.