The book "The Case of the Delfields" is written by Florence Finch Kelly and reveals the story of the mysterious girl Alison Delfield, who mysteriously disappeared in a small town. Her disappearance causes a wave of disputes, investigations and danger among local residents. The main character, a young journalist, decides to go at her own risk in search of the truth, not suspecting that the secret of the Delfield family hides many terrible secrets. This is a gripping story of love, loss, mystery and betrayal that will keep the reader in suspense until the last page.