Carolyn Keene

Nancy gets involved in mystery when she receives a valuable moonstone from an unknown person.

Elsa is working as a counselor at Green Spring Pony Club's summer camp, preparing the girls for a regional competition, when one of the horses is sabotaged and she must call on Nancy Drew for help.

Bess, George, and I volunteered to go to Costa Rica for some R&R: rest and research. See, Corcovado Ecologica, a popular resort and preserve, isn't only a beautiful getaway; it's also a great place to study three species of monkeys. Or so we thought.

Nancy Drew must use clues in a dead man's letters to find some unpublished musical manuscripts that will save an old man and his granddaughter from financial ruin.

Attending the annual Greek mythology gala at Oracle College, Nancy, Bess, and George race to assist when a student falls from a balcony in the middle of her speech, an accident the sleuthing trio links to collegiate sabotage.

A rare Chinese vase is stolen from a pottery shop. Nancy and the owner of the shop feel that locating "the leaning chimney" will provide the clue to the vase and other stolen articles.

On a winter vacation in Wisconsin, Nancy and her friends stay in a 200 year old castle where there is the rumor of a hidden treasure.