In March 1907, the lives of three remarkable people collided at a New York City brownstone where Mary Mallon worked as a cook.

They were brought together by typhoid fever, a dreaded scourge that killed tens of thousands of Americans each year. This gripping story reveals the facts behind of the woman who unwittingly spread deadly bacteria, the epidemiologist who discovered her trail of infection, and the health department that decided her fate. Young readers will be on the edges of the seats wondering what happened to Mary and the innocent typhoid victims. With glossary, timeline, list of well-known typhoid sufferers and victims, further resource section, author's note, and source notes.