Doctor Proctor's fart powder / Jo Nesbo ; illustrated by Mike Lowery.

Enhanced descriptions from Syndetics:

Bestselling Norwegian mystery author Jo Nesbø enters the world of children's books with Doctor Proctor's Fart Powder, the first book in this very funny middle-grade series. Filled with magic, wit, and bathroom humor, Doctor Proctor will keep boys and girls laughing until the end.

Eleven-year-old Nilly is new to the neighborhood, but he is quick to make friends: Doctor Proctor, an eccentric professor who invents wacky potions and powders; and brainy Lisa, who is always teased by the twin terrors Truls and Trym. All is good farty fun when Nilly and Lisa help Doctor Proctor develop his latest invention, a powder that makes you fart. The powder makes Nilly and Lisa VERY popular at school when they sell it for 50 cents a bag. (And they get revenge on Truls and Trym by giving them an extra-strength dose of fart powder that shoots them up into a tree!)

But when Doctor Proctor creates an industrial-strength version that can send people to outer space, the kids must go to great lengths to protect the invention and keep it out of the hands of their neighbors, who want to use the powder for evil purposes.

In the spirit of Roald Dahl and Lemony Snicket, Doctor Proctor offers a winning combination of humor, adventure, and absurdity that kids (of all ages) will love--proving that Jo Nesbø can keep you on the edge of the seat and make your sides split in equal measure.