Washoe County Library System

While staying at the Crooked House, the family home of their housekeeper Mrs. McGregor, the Aldens try to solve a riddle that will lead them to a hidden treasure.

When the Aldens agree to watch the house of a local author who has written a book about a vampire, they end up investigating activities that are suspiciously similar to those in his book.

Henry, Jessie, Violet, and Benny are not expecting a mystery when they offer to show their new neighbors around Greenfield, but when they uncover a series of coded messages hidden in historical documents, they realize they might still have a lot to learnabout their hometown's past.

While vacationing at a friend's country home, the four Alden siblings try to find a long-missing, priceless brooch and investigate the existence of a ghostly stream.