The grandfather clock gave a single chime. It was a quarter past one, but two hundred years in the past... Eleven-year-old Joe Raven is an inventor. He spends his time creating small gadgets with extraordinary power. After discovering a note from the mysterious Granelda seeking help to overcome a vicious curse, he and his sister, Beth, are catapulted back to 1789. With evil spreading and time running out, what will it take to defeat the Marble Curse? Joe's belief in gadgets, or Beth's confidence in something more?