Cassian, a modern archaeology student, accidentally touches an ancient Egyptian obsidian scepter and travels 3,000 years back to the Temple of Amun, where he is mistaken for a noble's male concubine by Mokhas, the all-powerful High Priest. Using his modern knowledge of science and military tactics, he survives crisis after crisis, and the two gradually fall in love despite their initial hostility. When the time portal opens during the grand planetary conjunction, Cassian smashes the scepter to save Mokhas—who takes a poisoned arrow for him—choosing to stay forever. Together they quell rebellions and are crowned co-rulers, forging an enduring legend of joint rule in ancient Egypt.
