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

Two brothers take summer jobs at a department store where a series of peculiar events brings them under suspicion.

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 f

A family, snowbound in a vacation cabin, discovers adventure in surrounding wild life, three children they find in the snow, and a search for a l

A young Canadian visitor helps the Alden family solve a mystery involving a lost coin collection.

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 f

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

Two brothers take summer jobs at a department store where a series of peculiar events brings them under suspicion.

A young Canadian visitor helps the Alden family solve a mystery involving a lost coin collection.

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 f

While on bicycle trip to their aunt's farm, the four Aldens help solve a mystery.