The book tells the story of Izzie and her dog Tango, who go on an adventure to find the missing letters A through Z. Along the way, they encounter various enemies who had stolen the letters. They use creativity and problem-solving skills to retrieve the stolen letters and return them to their rightful places. Eventually, they successfully restore the alphabet in the forest, and Izzie and Tango are hailed as heroes. The book teaches the importance of every letter in the alphabet and promotes bravery and determination.