An anonymous diary is a mystery with handwriting that is difficult to decipher. It is filled with technical drawings and chemical formulas. Was the destructive explosion an accident or an act of revenge?

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.

Nancy attempts to solve the mystery of the strange tapping sounds in the home of a retired actress.

Nancy Drew investigates when a doll goes missing at a sleepover party.

Terry Scott, a young archaeology professor, seeks Nancy's help in unearthing a secret of antiquity which can only be unlocked by three black keys. While on an archaeological expedition in Mexico, Terry and Dr. Joshua Pitt came across a clue to the buried treasure. The clue was a cipher carved on a stone tablet. Before the professors had time to translate the cipher, the tablet disappeared--and with it Dr. Pitt! Terry tells Nancy of his suspicions...

While trying to help a friend out of a difficulty, teenage detective Nancy Drew has a perilous experience in and around a deserted bungalow.

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

"Nancy, George, and Bess are attending a three-day overnight camp at the local zoo. They'll get to spend lots of time with all of the animals and learn about them, too. The best part is, they will be helping the zookeeper make toys for the animals, just like real staffers! But when the toys the girls make by day are disappearing at night, it looks like everyone is a suspect! Can Nancy tame this wild case, or will the zoo animals be without anything...

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 Drew investigates when a recipe for ice cream is stolen. Eight-year-old Nancy Drew has never considered herself a detective before. But after a mystery unfolds at a sleepover, Nancy and her friends Bess and George launch their own detectives club.