The Alden children are staying at the New England farmhouse where their grandfather grew up. There are many stories and legends about the old farm, and there's a woodshed near the house that holds a surprising secret... a secret that dates all the way back to the Revolutionary War!

The children are spending the summer on their own private island but there is a mysterious stranger on the island.

The Aldens search for carousel horses that have disappeared from an amusement park.

While helping fix up the old house their cousins have bought, the Aldens hear stories about its being haunted and find evidence suggesting that there may be a ghost there.

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, isolated in a storm at a small bus station, are led into a mystery centering on a polluted river.

When the Alden children accompany their grandfather to the Snow Haven Lodge, a series of odd occurrences threaten to disrupt the annual winter games.

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 mysterious disappearance of a reclusive neighbor's cat involves the Boxcar children in some complicated detective work.

"One day in the park, the Aldens' dog, Watch, comes across a mysterious box with a note inside. 'Congratulations!' the note says. 'You've found it!' The box is part of a game called Geocaching. Soon, Henry, Jessie, Violet, and Benny are searching all over town for hidden boxes and making friends with other kids in the geocaching club. But is one of the club members a thief?"--Page 4 of cover