The Jackal's Head — Elizabeth Peters

Althea Tomlinson says she has returned to Egypt to see the sights, and to chaperon a spoiled teenager through this strange and breathtaking desert land. The truth is more complex...and dangerous. Ten years ago, something here brought about her father's ruin and subsequent death -- and Althea intends to clear her disgraced parent's name and lay a dark past finally to rest. But there are some mysteries best left buried in the shifting sands. And a devoted daughter's search for answers is stirring up forgotten memories almost too painful to endure, and propelling her onward toward ancient tombs, legendary treasures, miraculous discoveries...and ever-closer to her own probable doom.