Grade 3–5—Nine-year-old Scab McNally has an overactive imagination and is on a mission, which is a worrisome combination. He enjoys dabbling in his homemade science lab in his basement and is ecstatic when he develops a particularly obnoxious-smelling sister repellent. Scab and his "smart times ten" twin do not get along at all, hence the need for the repellent. When Isabelle refuses to help him convince their parents to get a dog, he decides to sell his repellent to his friends; with the money, he plans to buy a puppy on his own. Unfortunately, his plans hit a bump when he and his best friend have an argument and his latest batch of repellent, which is in his backpack, is accidentally squashed. At the same time Isabelle has decided to help Scab—until she learns why kids have been teasing her at school. Scab is a likable, free-thinking boy who is full of charm and humor. He leaps before he thinks and that gets him into more trouble than he can handle. His many tips, diagrams, and facts scattered throughout are entertaining, as are the numerous comical black-and-white illustrations. This is the first book in a series, and kids are sure to be wondering what kind of trouble Scab will brew in his lab next.