Although modern medicine is capable of incredible feats, the ability to treat the human body follows hundreds of years of experimentation, at times with deadly results. When an epidemic of yellow fever strikes American soldiers in Cuba, Jesse Lazear journeys to the front. In a race against time, he puts himself in harm's way to uncover the source of the epidemic and prevent its spread. When a revolutionary science fiction writer anticipates modern blood transfusions, does anyone take him seriously? As Alexander Bodanov turns metaphor into medicine, he puts his own body on the line. And before much is known about the body's internal systems, a God-fearing scholar named Michael Servetus makes an incredible observation about human circulation. How do his religious beliefs bury the discovery until almost 100 years later?