Fourth grade Scab McNally has a twin sister that is always spying on him. Scab really wants a dog of his own but can’t afford one. When he creates a sister repellent spray that really stinks, he decides to sell it to his friends so he could save up money for a dog. When a bottle of his spray breaks open causing chaos in the schools, Scab apologizes to his sister which brings them together, and collectively they convince their parents to get a dog.  This fun story comes with many fact boxes of information and story enhancing pieces, several of which contain body function information that will entice many young readers.