When the children uncover a strange puzzle in a friend's back yard, it's the start of a "spy game" leading to gold. But first they must make sense of an old photo and a riddle, and learn just who is behind this mystery within a mystery.

While on a camping trip with their grandfather, the Alden children try to find out about the loud music and missing food that threatens to scare away other campers.

Grandpa Alden and the Alden children encounter danger, excitement, adventure, and mystery in a quiet island fishing village.

"Henry, Jessie, Violet, and Benny Alden are orphans looking for a place to live together as a family. Could a boxcar in the woods be their new home?"-- Provided by publisher.

Summer vacation on an almost private island gives the Aldens a challenge. Henry, Jessie, Violet and Benny used to live alone in a boxcar. Now they have a home with their grandfather and are spending the summer on the island. There is a mysterious stranger on the island with a secret--but that's not the only surprise in store for the Boxcar Children.

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.

The children are staying at the home of a famous inventor who was known for her one-of-a-kind clocks. All the clocks make noise especially at midnight, when there are enough chimes, gongs, and clangs to wake the whole house up! But the clocks aren't the only sound in the house at midnight. Someone or something is making a mysterious tapping sound. Who could be inventing trouble in the old house?

The Alden children head to their aunt's ranch for the summer and make an amazing discovery! Adapted from Gertrude Chandler Warner's story of the same name, this early reader allows children to start reading with a Boxcar Children classic.

When their favorite pizza restaurant almost goes out of business, the Alden children try to help their friends stay open while they find out who is behind all their problems.