Prudence Galewski doesn't belong in Mrs. Browning's esteemed School for Girls. She doesn't want an "appropriate" job that makes use of refinement and charm. Instead, she is fascinated by how the human body works--and why it fails.

Prudence is lucky to land a position in a laboratory, where she is swept into an investigation of a mysterious fever. From ritzy mansions to shady bars and rundown tenements, Prudence explores every potential cause of the disease to no avail--until the volatile Mary Mallon emerges. Dubbed "Typhoid Mary" by the press, Mary is an Irish immigrant who has worked as a cook in every home the fever has ravaged. But she's never been sick a day in her life. Is the accusation against her an act of discrimination? Or is she the first clue in solving one of the greatest medical mysteries of the twentieth century?