During a trip to Oregon, the Aldens are astonished when Watch discovers a backpack filled with valuables, a finding that compels them to learn what happened and return the backpack to its rightful owner.
While the Aldens are visiting a friend of Grandfather's at the beach, Benny finds a long-lost piece of a map to a legendary pirate treasure, a discovery that brings unwanted attention from fortune hunters.
While visiting a recent purchase of Grandfather's, a ghost town in the Rocky Mountains, the Aldens encounter a mystery involving a run-down motel and a woman who may be a ghost.
While helping their grandfather prepare for Greenfield's Winter Festival, the Alden children uncover a mystery surrounding the statue in the town square.
While visiting the seaport town of Ragged Cove, Massachusetts, the Alden children find the ship's log of the Flying Cloud, shipwrecked in 1869, supposedly during a mutiny.
The Alden children draw upon their resourcefulness to save the neighborhood firehouse from being torn down, while they also face a series of mysterious incidents connected with it.
Taking a shortcut through the Greenfield Cemetery, the Aldens stumble across a local superstition which maintains that visitors are required to leave gifts or suffer the wrath of a malevolent ghost, a suspicious tradition that prompts the children to expose the truth.
The Alden children visit a family friend at his apple orchard which is rumored to be haunted, but instead of a ghost they find that some of the family's valuable antiques are being stolen.