 Sherlock Holmes and Dr. Watson are going on a fishing trip, and while they are riding the train, they meet Watson s old friend Reggie Taunton. Taunton asks Holmes if the detective would mind helping him with an odd problem. Taunton s archaeologist uncle has sent him an authentic Egyptian mummy, and strange laughing sounds have been coming periodically from the sarcophagus. Holmes visits Taunton s home, and has dinner with Reggie, Reggie s fiancée, the fiancée s aunt, and an Egyptologist who knows Reggie s uncle. While they are dining, the mummy starts to make the noise, and Holmes quickly finds a very simple explanation for it. But in the course of examining the mummy and the sarcophagus, Holmes uncovers a more serious mystery.