The third caper is the zaniest yet for Beatrice Zinker, the irrepressible third grader who marches to the beat of her own drum--and does her best thinking upside down With several successful Operation Upside missions under their belts, Beatrice, her best friend Lenny, and Sam have made quite a name for themselves--they're the people who remind you there are infinite upsides to being yourself. But suddenly the unthinkable occurs--an imposter...