It is the 1950s, and America lives in fear of polio, a disease that kills or paralyzes its victims, particularly children. Determined to find a cure, Doctor Dorothy Horstmann hunts down polio where it lurks: in the blood. This discovery of hers, and an error by a competitor, catapults her closest colleague to a lead in the race. When she is asked to sink or validate his vaccine, Dorothy will also have to decide what is forgivable—and how much should be sacrificed—in pursuit of the cure.