How do you start fifth grade without your best friend?
Penelope wishes she were starting fifth grade with her best friend, Tim, who recently died of cancer. When everyone pairs off with friends from last year, Penelope is alone, with only her dad, the new janitor, to keep her company. Dad means well, but he keeps embarrassing her by acting more like a kid than a janitor. To ease her loneliness at school, Penelope begins writing secretly to Tim on "While You Were Out" notes. But when her messages mysteriously begin to be answered, Penelope realises that she's not alone in missing Tim.