Thamos loves Sais , a priestess .
Priestess is really Menes ' priestess Tharsis , for whom the high priestess Mirza is plotting marriage to Pheron , a treacherous general .
Thamos loves Sais , a priestess , but she is really Menes ' daughter Tharsis , for whom the high priestess Mirza is plotting marriage to Pheron , a treacherous general .