On April 22, 1721, the HMS Seahorse arrived in Boston from the West Indies, carrying goods, cargo, and unbeknown to its crew, a deadly virus. Soon, a smallpox epidemic had broken out in Boston, causing hundreds of deaths and panic accross the city. The clergy, including the famed Cotton Mather, turned to their standard form of defense against disease: fasting and prayer. But a new theory was also being offered to the public by the scientific world: inoculation. The fierce debate over the right way to combat the tragedy would become a battle between faith and reason, one that would set the city aflame with rage and riot. This book is a story of well-known figures such as Cotton Mather, James Franklin, and a young Benjamin Franklin struggling to fight for their cause among death and debate – although not always for the side one would expect. In the end, the incredible results of the epidemic and battle would reshape the colonists’ view of their destiny, setting for America a new course, a new covenant, and the first drumbeats of revolution.