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

Kitty and Johnny Blair, two famous actors, adopt baby twins who were mysteriously found in a boat along the river. The cruel Blairs have only adopted the babies as a publicity stunt, as they hope to raise the children as actors, which will help their own careers. Nancy sets off to find their real mother and take them away from the Blairs.

Nancy must figure out the connection between a mysterious diary and a suspicious house fire.

Thrilling, dangerous adventures confront Nancy Drew while on a safari in East Africa with a group of American college students. Excitement runs high as the teen-age detective delves into the theft of a fabulous sapphire formed by nature millions of years ago. The mystery starts in Nancy’s home town. Her lawyer father’s client, Floyd Ramsay, who fashions beautiful and unusual synthetic gems, is accused of stealing the magnificent spider sapphire and exhibiting it as his own creation. Mr. Ramsay’s enemies blackmail him and by their vicious acts try to deter Nancy from going on the safari. Readers will join Nancy as she uncovers a nefarious scheme and solves the strange disappearance of an injured jungle guide.

The Hidden Window Mystery: Nancy and her friends, Bess and George travel to Charlottesville, Virginia in search for a missing stain-glass window.

Nancy becomes involved in a double mystery concerning a haunted bridge and jewel thieves.