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

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

When Nancy Drew and her friends arrive at Misty Lake, they meet pretty, red-haired Cecily Curtis, who seeks Nancy’s help in solving two mysteries. One concerns Cecily’s fiancé, Niko Van Dyke, a popular singer who believes that his record company is cheating him of royalty payments. The other invovles a family treasure hidden before the start of the Civil War; Cecily’s only clue is half of a gold locket. Nancy’s investigations lead her to Pudding Stone Lodge, where the sinister Driscoll family lives. Strange coincidences give Nancy plenty of opportunity to test her sleuthing skills. Braving a series of dangerous situations and discouraging developments, the alert young detective perseveres in her attempts to solve both mysteries and reveal the astounding secrets of Pudding Stone Lodge.

Blue bells will be singing horses! This strange message, attached to the leg of a wounded homing pigeon, involves Nancy Drew in a dangerous mission. Somewhere an elderly woman is being held prisoner in a mansion, and Nancy is determined to find and free her. Meanwhile, the young detective’s close friend, Helen, begs her to solve a second mystery. Helen’s grandparents, the Cornings, are frightened by a sinister wheel of blue fire that appears after dark in the woods outside their home at lonely Sylvan Lake. When Nancy discovers the significance of the eerie signal, she also learns that her two mysteries are connected.

What secret life-giving power does the exquisite ivory elephant charm contain? Can the trinket really protect its wearer from all harm? Nancy Drew finds out when the owner of the Bengleton Wild-Animal Show asks her to investigate one of the performers who may be involved in some mysterious illegal scheme.The girl detective’s assignment becomes complicated when the elephant trainer’s young assistant, Rishi, seeks refuge at the Drew home from his cruel foster father, Rai.While following clues to help the boy find his real father, Nancy learns about an eerie abandoned house. She is harassed by its strange owner, Anita Allison, and the fiendish Rai. How Nancy uses the ivory charm, reunites a maharaja with his son, and brings the evildoers to justice will mystify readers from beginning to end.