Cassandra loves school-- so much that she never, ever wants to leave! One Friday, Cassandra decides she is going to stay at school. She stays after the nice teacher leaves. She stays while the janitor with a tattoo mops the floors. She stays after the mean principal turns off all the lights and goes home. She plays with the plasticine and the unit blocks until after dark, when her mom and dad realize she is not at the dinner table. They go to the school and take her back home. The next day, Cassandra gets up and puts her school clothes on. Her parents explain that it's Saturday and there is no school on Saturday. Cassandra takes her bike and heads off anyway-- but the school is locked. On her way back home she goes by the School Store and places an order. The next day is Sunday, and Cassandra looks out the window to find a brand-new red-brick school with a nice teacher, a mean principal, and a janitor with tattoos -- in her back yard. She runs out the door, into her new school, sits down at a desk in the classroom with the nice teacher, and plays with the unit blocks and plasticine!