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.

One warm night four children stood in front of a bakery. No one knew them. No one knew where they had come from. Henry, Jessie, Violet and Benny are orphans.They discover an old red boxcar that provides them shelter from the storm.

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.

While visiting Chicago with their grandfather, the Alden children begin receiving mysterious clues to a treasure hunt. Includes related puzzles, games, and activities.

While Tate Radison was filming his last movie, a lot of odd things happened. Now Tate wants to keep his presence in Greenfield a secret to avoid many more mishaps. But trouble follows him.

While visiting the Florida Keys, the Aldens encounter suspicious characters, strange incidents at night, and a plot to steal valuable coral.

Four orphaned children run away and live in a boxcar, until they are found by their grandfather. Includes a biography and photographs of the author.

Henry, Jessie, Violet, and Benny are given the opportunity to be extras in a movie about the Alamo, but they are called upon to use their sleuthing skills when Claire, the star of the film, is implicated in the theft of a valuable ring.

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?