Ding, Dong! Ding, Dong! When Christina discovers that the Liberty Bell hanging in Liberty Center is a fake, she enlists Grand and two Philadelphia friends to help her find the real one. But time in running out! They have to solve this mystery before the Fourth of July! See if you can crack this mystery. Some mysterious historical characters, including Ben Franklin, George Washington, and Betsy Ross, offer them clues. But are they actors… or are they ghosts? Along the way, the kids are chased by Redcoats, cornered in a creepy old ship, and learn about the birth of the United States! So grab your tri-corn - it's time for a trip back in time!