In a flashback late-Victorian beauty Ruby a divorcee with a shady past calculatingly marries rich Egyptologist Nigel who installs her at his Cairo estate while he digs for mummies. Bored Ruby undertakes to recover a friend's letters from Baroudi. But when she meets the blackmailer mutual attraction leads to an affair. As Ruby gets in deeper she finds Baroudi is even more unscrupulous than she dreamed.