At their newly founded school, Samuel Hood and his daughter, Caroline, promise a groundbreaking education for young women. But Caroline has grave misgivings. After all, her own unconventional education has left her unmarriageable and isolated, unsuited to the narrow roles afforded women in nineteenth-century New England.

When a mysterious flock of red birds descends on the town, Caroline alone seems to find them unsettling. But it's not long before the assembled students begin to manifest bizarre symptoms: rashes, seizures, headaches, verbal tics, night wanderings. One by one, they sicken. Fearing ruin for the school, Samuel overrules Caroline's pleas to inform the girls' parents and turns instead to a noted physician, a man whose sinister ministrations--based on a shocking historic treatment--horrify Caroline. As the men around her continue to dictate, disastrously, all terms of the girls' experience, Caroline's own body begins to betray her. To save herself and her young charges, she will have to defy every rule that has governed her life, her mind, her body, and her world.