While visiting a recent purchase of Grandfather's, a ghost town in the Rocky Mountains, the Aldens encounter a mystery involving a run-down motel and a woman who may be a ghost.

"The Aldens are at Wildcat Crossing, a recreated frontier town full of cowboy fun. But when horses disappear and other pranks threaten to ruin the Wild West show, the Boxcar Children must find out who's the varmint causing all the trouble"--

When the Alden siblings go camping on Padre Island, they help save a rare type of sea turtle from a mysterious sabotager.

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 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.

When their grandfather arranges for them to spend two week at Sunny Oaks, the four Alden children enjoy settling into the routines of farm life but become suspicious about a mysterious horse locked in the stables.

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.

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.

The Aldens search for carousel horses that have disappeared from an amusement park.

The Aldens agree to help Grandfather's friend fix up Skeleton Point, an old mansion. Skeleton Point is filled with old skeletons belonging to its former owner, and townspeople have seen the skeletons walking through the house.