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 shop.

But twelve-year-old Manya isn't like most kids. She’s an aspiring scientist. The cheap laughs at Pranks-A-Million don’t interest her — but the science behind the pranks does. After all, even edible snot and stink bombs rely on chemical reactions.

Manya and her best friend, Isaac, are thrilled when their parents agree to sign them up for Serious Science. The after-school class is everything they’ve ever dreamed of: the science is fascinating, their teacher is supersmart, and none of the experiments he gives them is designed to stink, explode, or embarrass anyone.

Things are looking up until one day Manya comes back from Serious Science to find two police officers in the store. A trick cigar bought at Pranks-A-Million burned off a customer’s eyebrows. Later, one of their Toe Jam Donuts makes someone sick. Just a couple of pranks gone wrong? Maybe. But when a whoopee cushion kills an innocent person, the joke is over. The cops swoop in and arrest Manya’s parents for murder.

It's up to Manya now to prove their innocence. Suddenly, the science behind all those embarrassing pranks becomes very important indeed.