The year is 1348. Thomas, a disgraced knight, has found an orphan of the Black Death in a Norman village. An almost unnerving picture of innocence, she tells Thomas that the plague is only part of a larger cataclysm—that the fallen angels under Lucifer are rising in a second war on Heaven. But is it delirium or is it faith?

She believes she has seen the angels of God. She believes the dead speak to her in dreams. And now she has convinced the faithless Thomas to shepherd her across an apocalyptic landscape to Avignon. There, she tells Thomas, she will fulfill her mission. There her true nature will be revealed. And there Thomas will confront an evil wrestling for the throne of Heaven, and which has poisoned his own soul.