The boxcar children travel to Maine, take canoes into the wilderness and live in a house exactly like the one on Surprise Island, except the Maine house is brown, not yellow. They untangle the mystery of the two houses. Relates the exploits of the four Alden children as they locate a missing man. The Boxcar children are determined to solve the mystery that surrounds an old yellow house on their grandfather's property. Strange things have happened...

The Alden children and their grandfather are hiking down from Flat Top when a rockslide reveals a cave with a big secret.

Henry, Jessie, Violet, and Benny, working behind the scenes of the Greenfield Museum's special exhibit, attempt to solve the problem of missing Egyptian treasures.

The Alden family, snowbound in a vacation cabin, discovers adventure in surrounding wild life, three children they find in the snow, and a search for a lost recipe.