The Aldens, while testing the latest version of their favorite computer game, are surprised to find messages directed specifically at them.

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.

The Aldens try to help a visiting Russian gymnast who is surrounded by mysterious people and events and who seems to have a secret.

"Henry, Jessie, Violet, and Benny are spending the summer on a houseboat! Throughout the journey, the children have the feeling they're being watched-- and they are. Someone wants something on their boat, and he'll stop at nothing to get it. Can the Boxcar Children figure it out what it is before it's too late?"--P. [4] of cover.

The Alden children travel on a Mississippi paddle-wheel steamer to visit an old family friend in his cabin near Hannibal, Missouri, and try to discover who is responsible for the mysterious activities near the house.

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

The Alden children have an adventure as they journey along with the Little North Railroad in two cabooses rented for the summer by their grandfather.

When the Aldens visit Yellowstone they discover a map showing the way to an old cabin where gold is supposedly hidden, but they encounter lots of interference in their attempts to hike the trail.

The Alden children stumble upon a mystery when they enter their dog, Watch, in a contest that could lead to fame and fortune, but where things keep going wrong.

The Aldens are excited to learn about beekeeping. But when equipment goes missing, they have more than honey to harvest -- they have a mystery to solve!