
When Susan Cushing first consults Holmes about the disappearance of her sister Mary, he shows little interest in the case. But then, at Christmas, Susan receives an alarming present in a cardboard box, and Holmes is quickly on the trail of a dangerous criminal.
The Mazarin Stone, a famous jewel, acts as a magnet for crime. Holmes investigates the latest and perhaps most curious episode in its adventures.
The police are baffled by the murder of Willoughby Smith, and Inspector Hopkins looks to Holmes to solve the case.
A man dies suddenly of a mysterious fever, and Holmes suspects murder.