Mandie and the Night Thief (Mandie, Book 37)

Mandie and the Night Thief (Mandie, Book 37) by Leppard, Lois. mass_market edition. ISBN: 9780764226403.

After staying with the Pattons only a couple of days, Mandie and her friends and family realize jewelry is mysteriously disappearing overnight. So far Mandie is missing a cherished locket; Celia, a silver bracelet; and Mandies grandmother, some of her own jewelry. If Mandie and her friends investigate the strange noises in the night, will they find the thief? Or is the house haunted like some say it is? When Joe leaves early to go back to college, a sad Mandie is more determined than ever to solve the mystery of the missing jewelry.