The Aldens' boxcar is the perfect place for games, picnics, sleepovers, and fun. But is it also the perfect place for ghosts? When strange things start happening there, Benny is convinced that the boxcar is haunted. Will the Aldens be able to scare away the spook...or is it good-bye, boxcar?

The Alden family rents a houseboat to drift down the river, and encounters a mystery in the little towns along the river, involving a fast black car.

The Alden children help out a storeowner at the Hope Harbor Mall and discover that someone is tampering with the merchandise shipments.

When their favorite pizza restaurant almost goes out of business, the Alden children try to help their friends stay open while they find out who is behind all their problems.

On a camping trip to Arizona with their grandfather, the Alden children search for a lost gold mine.

The Aldens participate in a three-day bicycle ride and soon find that someone seems to be intent on keeping others from completing the event.

While sightseeing at the Alamo, the Boxcar children investigate the disappearance of a priceless ring from the Alamo museum.

The Aldens start a business producing birthday parties and find themselves investigating a series of robberies taking place during their parties.

When the Alden children accompany their grandfather on a trip to Seattle, they discover clues throughout the city, seemingly planted just for them.

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.