'Secret Mark' Summary

Lucile Tucker, a college student working part-time at the university library, stumbles upon a puzzling sight one evening. She catches a glimpse of a young girl stealing a valuable book from the collection and disappearing right before her eyes. Unable to bear the thought of the child being apprehended by the police, Lucile enlists the help of her friend Florence to investigate the matter themselves. Their quest leads them through dangerous streets and unsavory parts of Chicago, as they try to unravel the reason behind the book theft. Along the way, they encounter a mysterious elderly man in a crumbling cottage and discover a cryptic mark inside the front covers of the stolen books. As they inch closer to the truth, they realize they are being watched, adding an element of danger to their investigation. Determined to uncover the secrets behind the Secret Mark, Lucile and Florence press on, facing challenges and threats that test their friendship and courage.