The Snake, the Crocodile and the Dog — Elizabeth Peters

Aboard a boat traveling up the Nile, their delightful (but catastrophically precocious) son, Ramses, back in England, Amelia Peabody and her handsome husband, Emerson, just might have a second honeymoon while they search for Nefertiti's tomb. On the other hand, they might be heading toward murder. Or worse. A beautifully exotic slave woman, an enigmatic Siamese cat, and a den of conspirators unite to snatch away Amelia's happiness unless she reveals a secret she cannot ethically, morally, or in any other way disclose. So now, as the Emerson-Peabodys arrive at the remote desert site of Amarna, they will confront danger behind the sand dunes, a nefarious kidnapping plot, and a villain in disguise among their retinue. Amelia is tantalizingly close to the most fabulous discovery since King Tut's tomb, but as hard as she digs, what she uncovers is a shocking present-day peril: the loss of treasures far more precious than any antiquity--her husband's love or both their lives!