About the Bookthe story opens with Nancy tending her prize delphiniums, when a mysterious carrier pigeon falls out of the sky. The message, "Bluebells are now Singing Horses," is so odd, it causes her to contact the registry for the birds. Meanwhile, housekeeper Hannah falls and must be taken to the local orthopedist's office. Dr. Spires later confides to Carson Drew and Nancy that he was forced to tend an elderly woman for her shoulder -- the drivers of a car blindfolded him to disguise her location, leading him to believe she was a prisoner. The only clue to her identity is a bracelet with a family crest, and the doctor's belief that larkspur lane was the locale. Nancy of course immediately sets out to track the crest, discovering it belongs to the Eldridge family of St. Louis.
In the meantime, the registry contacts Nancy about the pigeon, suspecting something criminal is involved. Effie Schneider, a dizzy young girl, serves as Hannah's substitute, and gets in on action when Nancy attempts to track the carrier pigeon's flight into the country. A strong woman attacks Nancy downtown, then steals the bracelet from her. Due to threats of intruders and increasing danger, the Drews accept Helen Corning's invitation to visit Sylvan Lake. Mr. Drew and Nancy sneak out of the house, and leave in Nancy's new green and black roadster for this locale.
Coincidentally, Nancy rescues a young Eldridge child from a mishap at the lake, and learns an elderly relative is missing. Nancy and Helen explore the vicinity for some time, finally finding "L.S. Lane." Near the little used road is an estate surrounded by an electrified fence, and also surrounded by delphiniums. Elderly patients abound in wheelchairs on the grounds. Nancy fortunately finds Mrs. Eldridge near the fence, and finds out she is indeed a prisoner. Nancy and Helen disguise themselves as old lady and nurse, and enter using the password, "Singing Horses." Nancy reaches Mrs. Eldridge, rescues her, and gets her safely away with Helen before becoming a prisoner of the evil doctor and his partners in crime, who are kidnapping wealthy elderly people and forcing them to sign over money and securities. She escapes from her cistern prison, and sabotages their airplane, just as the police arrive.
- Genre: Mystery
- Theme(s): Family, Children's
- Author: Carolyn Keene
- Publisher: Applewood Books
- ISBN: B000MZRC6S
Hardcover Release North America Dec 31, 1969
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