插畫：Frank W. Dormer
Aggie and Ben are back with another adventure in three short chapters just right for beginning readers. Ben and Aggie are playing fetch in the park. When Ben throws too far, Aggie doesn't come back! Ben looks and looks, but he cannot find her. It is the worst day ever. Ben's sadness turns into determination as he retraces his steps, makes posters, and enlists other people to help turn Aggie from a lost pup to a found one.