The Hidden Treasure Mysteries feature a brother and sister detective team who investigate long-forgotten mysteries as they hunt for lost treasures.  This package is great for middle readers from 8 to 11 years old.

In The Puzzle in the Portrait, the junior detectives discover their own family history as they solve a 120-year-old family mystery.

In The Mystery of the Ancient Coins, the two hunt for five ancient gold coins that have been passed down in a family for generations, then disappeared without a trace 40 years ago.

In The Mystery on Observatory Hill, the detective team spends the summer in Germany and hunts for long-missing scientific notebooks at a research park for astronomers.

Eleanor Rosellini, the author of the series, is a writer and environmental activist who has lived in Needham for seven years.