Jewels are discovered stolen from a company safe, and a letter with the thumbprint of the company owner’s nephew is found at the scene of the crime. The evidence seems indisputable, and he’s quickly arrested and charged with larceny. But was it an inside job?

Dr. Thorndyke is called to investigate the case. With his medical, scientific, and legal background, he tries to uncover novel evidence that could shed light on the crime.

This novel is the first in the long-running series of detective stories featuring Doctor Thorndyke.