A whoopee cushion turns deadly in this new middle-grade mystery from acclaimed author Vicki Grant. The best Halloween costumes. The funniest pranks. An endless supply of chocolate fudge that looks exactly like dog poo. Most kids would love it if their parents owned a joke store. But twelve-year-old Manya isn't like most kids. She's not interested in the cheap laughs at Pranks a Million. She loves science. She wants to save the world...