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

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.

The Alden children save an old woman's house, land, and all the animals in her animal shelter from greedy contractors.

Strange things are happenikng at the Wagner Farmhouse, and the Aldens' new friends are being blamed. Is the house haunted by the ghost of practical joker Horace Wagner? Or is someonme trying to destroy the museum's chances for success?

The Alden children are helping their new neighbors build a tree house when they discover an attic window that not even their neighbors knew about.

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 have another mystery to solve when they visit a castle and must figure out which of the guests has stolen the Stradivarius violin.

Henry, Jessie, Violet, and Benny hav3e promised Grandfather a vacation from mysteries during their island visit. But the romise proves hard to keep when things start to go missing. Then an old fisherman tells Benny of the island's ghost horse, and late that very night benny sees a mysterious stallion galloping down the beach. Could the ghost horse have something to do with the disappearances?

When the Alden children and their grandfather visit Everglades National Park in Florida to solve the mystery of a missing ranger, they discover that a panther provides a clue.

The Alden children are thrilled when a famous orchestra comes to their town to perform, and when an original Mozart score turns up missing, they solve the mystery of its disappearance.