While solving the mystery of an old man's disappearing fortune, Nancy ends a family feud and reveals the identity of an orphan of unknown parentage.

Nancy's sympathy for a pair of adopted twin babies leads her into a surprising mystery.

Nancy arrives in Phoenix, Arizona, eagerly looking forward to a fun-filled vacation at Shadow Ranch but finds herself embroiled in a baffling mystery involving a phantom horse and buried treasure. Local people believe that the ghostly animal is carrying out the curse of Dirk Valentine, the romantic outlaw who was killed many years ago at Shadow Ranch, where he had gone to fulfill a promise to his sweetheart. Suspecting that a treasure hidden by Valentine...

Nancy becomes suspicious of a secret society and is drawn to investigate.

Nancy receives a letter meant for a British heiress who has the same name and, in her attempts to contact the other young woman, faces danger from a man who operates a Lonely Hearts Club mail fraud.

Summary: Asked to locate a stolen necklace of unusual value, Nancy soon discovers that strange and dangerous people are responsible for the theft.

Nancy Drew investigates when a pony from the petting zoo keeps escaping from his pen.

Nancy Drew and her friends go on a ghost hunting expedition and become involved with a gang of thieves who concentrate their activities on collectors of valuable shells.

Nancy Drew's latest involvement in a mystery begins in her home town and concerns a synthetic sapphire with a spider embedded in it, and the strange disappearance of Ned Nickerson.

Warnings cannot stop Nancy from going to Scotland to solve the mysteries of a missing family heirloom and the fate of the flocks of stolen sheep.