Book Summary:
It has been three years since the adventure with the Sibylline books. This time Willie digs deep into the old trunk of treasures his great-grandmother left in her attic and finds an old and strange Egyptian map. Uncertain where the map is leading him, Willie follows its siren call to try to uncover its secrets. But this journey takes him to Cairo with its mysterious Egyptian pyramids and subterranean caverns below the Great Sphinx. There Willie and his new friend Shannon find themselves trapped in a lost world – one with an ancient civilization long thought to have vanished from Earth thousands of years ago.