Jack and Annie are whisked back in time by the magic tree house to Old Philadelphia in 1787. Their mission, given to them by Morgan le Fay, is to help one of America’s most famous Founding Fathers, Benjamin Franklin. Upon arrival, they find themselves amidst the heat and tension of the Constitutional Convention. They must navigate historical streets to find “Dr. Ben” and assist him with a task described as daring, dangerous, and almost impossible. Along the way, they encounter other historical figures like George Washington and Alexander Hamilton. The story blends time-travel adventure with educational facts about the creation of the U.S. Constitution and Franklin’s legacy as an inventor and diplomat.