Mia Montrose is a 21st-century Australian woman with a Doctorate in Ancient Languages who has just scored the most promising job of her career and begins to experience mysterious happenings and forces beyond her control. Ashlee Granville is a 19th-century clairvoyant, forced to suppress her talents as she enters the marriage market of English upperclass society. Lillet du Lac is a 13th-century woman, priestess of an ancient order who are making their last stand against the Roman Catholic Franks at the giant hill fort of Montségur. Despite the time, distance and cultures that separate them, these women all belong to an ancient bloodline of Grail kings and they are each compelled to visit an ancient mountain in the Sinai. This mountain contains the keys which may unlock a gateway to a dimension of light and the Gene of Isis.