In the third adventure of Robert Arthur's classic mystery series, Pete, and Bob encounter Ra-Orkon, the mummy of an Egyptian prince dead for three thousand years. But sometimes the dead don't rest easily. As it turns out, Ra-Orkon has things to say, and the Three Investigators, along with their new friend Hamid, have to answer some puzzling questions. How can a mummy speak? What is he trying to say? And can the boys discover his secret before they and others fall victim to the mummy's ghastly curse?