[2] 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.

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.

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.

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.

She sends Eldridge safely away with Helen before being imprisoned by the evil doctor and his partners, who kidnap wealthy, elderly people and force them to sign over money and securities.

A subplot involving supernatural events at Helen Corning Archer's in-laws' summer place on Sylvan Lake (ghostly blue wheels of rolling fire) leads Nancy there.

Collectors speculate publisher Grosset & Dunlap commissioned an updated illustration of the same scene during the transition from Gillies to new series artist Rudy Nappi in 1953.