Henry, Jessie, Violet, and mystery, and much more, in an old attic. The Aldens' neighbor, Lina, thinks that her great-aunt hid an unknown treasure there years ago.

Four orphaned children run away and live in a boxcar, until they are found by their grandfather. Includes a biography and photographs of the author.

The Alden children plan to ride in their boxcar at the Greenfield Founders' Day Parade, but the newly refurbished boxcar is stolen a couple of days before the big event.

When the Aldens stay at an old Kansas inn, Harry, Jessie, Violet, and Bennie try to figure out why guests travel great lengths to visit it.

The Boxcar children must track down an instrument thief in time to save Greenfield's music festival from disaster.

When the Alden children join a group of volunteers to fix up an old house for senior citizens, they try to explain the puzzling behavior of their coworkers as well as investigate some unusual events.

When the Aldens help a friend of their grandfather's to build the world's largest yo-yo, they soon discover that more than one person is trying to prevent them from finishing the job--and for more than one reason.

A friendly writer with a metal detector, the mysterious inhabitants of a tower house, and the discovery of a locket in the sand are ingredients for the Aldens' latest mystery.

The Alden children investigate when Mrs. Murray's jewels are stolen during a party for the Starlight Skating Troupe.

While on a cruise with their grandfather, the Alden children help discover who is behind the mysterious troubles of the ship--disconnected phone lines, engine trouble, a man overboard--and still have fun sightseeing, eating, and swimming.