Time for Andrew: A Ghost Story - Mary Downing Hahn

Andrew can feel the presence of his ancestors in Great-Aunt Blythe's old house. His fantasies of ghosts and the past become all too real when another Andrew, who lived at the beginning of the century and died young, appears. When he goes to spend the summer with his great-aunt in the family's old house, eleven-year-old Drew is drawn eighty years into the past to trade places with his great-great-uncle who is dying of diphtheria.