Beatrice is the convent's librarian. For years, she has shunned the company of her sisters, finding solace only with her manuscripts.

Then, one carnival night, two women, bleeding and stricken, are abandoned outside the convent's walls. Moments from death, one of them presses something into Beatrice's hands: a bewitching book whose pages have a dangerous life of their own.

But men of the faith want the book destroyed, and a zealous preacher has tracked it to her door. Her sisters' lives - or her obsession. Beatrice must decide.

The book's voice is growing stronger. An ancient power uncoils. Will she dare to listen?