The Curse of the Pharaohs — Elizabeth Peters

Amelia Peabody and Radcliffe Emerson, heroic survivors of Crocodile on the Sandbank, are called back to Egypt by Lady Baskerville to complete the excavation of a recently discovered tomb. The dig had been left unfinished by her newly dead--and possibly murdered--husband, Lord Baskerville.

The locals say this particular tomb is cursed. More and more of the native workers die in inexplicable accidents. Everyone--except Amelia and Radcliffe--holds the curse responsible. When Lord Baskerville's missing heir reveals himself to Amelia, she begins to piece together the mystery surrounding the tomb and Lord Baskerville's death.

Racing to uncover the truth, she and Radcliffe find Lady Baskerville more concerned with the contents of the tomb than with catching her husband's killer. Is there a flesh and blood murderer loose, or is it The Curse of the Pharaohs