Charles Tang

At an old library, the Alden children discover a boy who needs their help and a stranger who is after a valuable object they found in the library.

Benny wants adventure and finds it as he and the other Alden children help uncover the plan of those who would prevent ballooning from coming to Lloyd's Landing.

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.

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.

While canoeing and backpacking near Timberwolf Lake, the Aldens receive strange warnings to stay away from the area and stumble upon clues to a missing cache of stolen coins.

When the Alden children accompany their grandfather to the Snow Haven Lodge, a series of odd occurrences threaten to disrupt the annual winter games.

Someone is trying to put Aunt Jane's motel out of business, but the Alden children aren't going to let that happen.

While on a cruise with their grandfather, the Alden children help discover who is behind the mysterious troubles of the ship--disconnected phone lines, engine trouble, a man overboard--and still have fun sightseeing, eating, and swimming.

The Aldens investigate when the new coach of their community basketball league has her Most Valuable Player trophy stolen.

When the Alden children set out to solve a jewelry store robbery, they find they must also deal with a mysterious thief who steals their favorite cereal.