Nobby, short for Zenobia, meets an older girl, Zilla, when her family goes on holiday. Zilla is developmentally disabled, but much more fun than the average teenager. The friendship grows until Uncle Chad shows up. He is snooty and sometimes unthinkingly cruel to Zilla. Prejudices and attitudes take a surprising turn when Uncle Chad gets hurt during a storm and it is Zilla who generously comes to the rescue.