Amelia Peabody, that indomitable product of the Victorian age, embarks on her first Egyptian adventure armed with unshakable self-confidence, a journal to record her thoughts, and, of course, a sturdy umbrella. On her way, Amelia rescues young Evelyn Barton-Forbes, who has been "ruined" and abandoned on the streets of Rome by her rascally lover. With a typical disregard for convention, Amelia promptly hires her fellow countrywoman as a companion and takes her to Cairo. Eluding Evelyn's former lover, who wants her back, and Evelyn's cousin Lord Ellesmere, who wishes to marry her, the two women sail up the Nile to an archaeological site that is home to a rather lively mummy. Soon strange visitations, suspicious accidents, and a botched kidnapping convince Amelia that there is a plot afoot to harm Evelyn.
