The Fourth Plague

A secret criminal society known as the Red Hand has taken root in England, bringing extortion, murder, and political terror in its wake. Professor Antonio Tillizini, an Italian criminologist with unorthodox methods and a long history with the organization, is called in after a suspicious burglary points to a far larger scheme. At the center of the mystery are two rare Renaissance medallions and a secret dangerous enough to hold a nation to ransom.
As the Red Hand closes in, Tillizini must uncover its leaders before their most ambitious plan can be carried out.