Cynthia Voigt 
Vandemark Mummy [EPUB ebook] 

A mummy has gone missing! Its not a terribly valuable mummy, but its disappearance spells big trouble for Phineas and Altheas father, who is the curator of a small collection of Egyptian antiquities bequeathed to the college where he works. A whispered phone call leads Phineas and Althea to the vandalized mummy without revealing the identity of the thief. Then someone far more important to Phineas than a fifteen-hundred-year-old mummy vanishes. In spite of what the police think, he knows his sister would not have run away, and he knows shes in grave danger. But can he unravel the mystery in time to save her life?