A series of practical jokes at a restored nineteenth-century farmhouse makes the Aldens wonder if the ghost of its builder is at work.

When an elderly friend is injured, the Alden children offer to help him with his window-washing business in their small town of Greenfield and agree to help him solve a riddle that has arrived in a mysterious invitation.

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

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.

The Alden children search for buried treasure on Blizzard Mountain, but a mysterious rival treasure hunter is determined to chase them off the mountain.

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.

"The winter sports season is here, and the Aldens are excited about all the snow activities--especially snowboarding. But soon they find themselves in the middle of a mystery surrounding a star athlete and a stolen snowboard"--

The Aldens are excited to be playing in their summer soccer league, until someone begins sabotaging the teams.

The four Alden children, aged six to fourteen, uncover a mystery while volunteering at a food pantry for the needy.

People line up around the block to buy Mama Tova's cupcakes. But who could be trying to steal her secret recipe? The Boxcar Children follow clues to a cupcake contest, where they must use their mystery-solving skills to find a thief.