The Adventure of the Pharaoh's Curse

Norris Wentworth buys and brings an Egyptian sarcophagus to display at the world famous Tremane Museum. Wouldn't you know it, there's curse on the darn thing. The six previous owners have all kicked the bucket under mysterious circumstances. Needless to say, Wentworth becomes victim number seven but is he really the victim of a mummy's curse or is there some other motive in this wild, wild case?