The Password to Larkspur Lane is the tenth volume in the Nancy Drew Mystery Stories series. It was first published in 1933 under the pseudonym Carolyn Keene. The actual author was ghostwriter Walter Karig in his third and final Nancy Drew novel and his final appearance for the Stratemeyer Syndicate. Due to Karig's death in 1956, this book and his other two Nancy Drews, as of January 1, 2007, have passed into the public domain in Canada and other countries with a life-plus-50 policy. Plot summaries 1933 edition The story opens with Nancy tending her prize delphiniums when a mysterious carrier pigeon lands in her yard. Nancy contacts the registry for the carrier pigeon. Meanwhile, housekeeper Hannah Gruen takes a fall and must be treated at the local orthopedist's office. Her attending physician, Dr. Spires, confides to Carson Drew and Nancy that he was forced to tend an elderly woman for her shoulder under peculiar circumstances: the driver of a car blindfolded him when they drove him there, so he would not be able to guess her location, but the doctor believes their destination might have been someplace called Larkspur Lane. Events led him to believe the patient was being held prisoner. The only clue to the woman's identity is a bracelet with a family crest. Nancy, of course, sets out to track the crest, discovering it belongs to the Eldridge family of St. Louis. In the meantime, the pigeon registry contacts Nancy about the bird, suspecting criminality is involved. Effie Schneider, a foolish girl who serves as Hannah's substitute, gets in on the action when Nancy attempts to track the carrier pigeon's flight into the country. A ferocious woman attacks Nancy and steals the bracelet from her. Due to threats of intruders and increasing danger, the Drews temporarily retreat and accept Helen Corning's invitation to visit Sylvan Lake. Coincidentally, Nancy rescues a young Eldridge child from a mishap at the lake and learns that an elderly relative is missing. Nancy and Helen explore the vicinity, finally finding "L.S. Lane". Near the little-used road is an estate surrounded by delphiniums and an electrified fence. Elderly patients are outside on the grounds. Mrs. Eldridge is also outside near the fence and reveals she is indeed a prisoner. Nancy and Helen disguise themselves as an old lady and her nurse, and enter using the password "singing horses". Nancy reaches Mrs. Eldridge and