Nancy Drew's keen mind is tested when she searches for a missing will.

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?

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

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.