When Nancy searches through the knapsack of an amnesia victim, she finds an unusual ring. Before long, she is caught up in a second assignment from a beautiful harpist. Nancy's discoveries reveal an important connection between the hospital patient, the harpist, and enemies from abroad.

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. Nancy is determined to find and free Mrs Eldridge. While working on the case, the young detective's close friend, Helen Archer, begs her to solve a weird mystery. Helen's grandparents, the Cornings, are frightened by a sinister wheel of