This turned out to be a time travel book (1st in a series). Chloe Kingsley is visiting her archaeologist sister in Egypt when she enters a forbidden chamber at the right time and place and wearing a special significant necklace. She is suddenly transported to ancient Egypt into the body of RaEmh...
Part two in this series of stories about Chloe and Cheftu. This is set for the most part on islands near ancient Greece, in what Chloe thinks is the Minoan culture that her mother has studied. Eventually the two of them figure out that this is actually Atlantis, and of course they are there at th...