While comically rescuing a dwarf from Villeneuve's bear-baiting ring, Bonne catches the eye of Radegonde Putemonnoie, a widow with unimaginable wealth who possesses uncanny beauty and is soon to be a mother.

When English mercenaries lay siege to Villeneuve, feeling grows against Radegonde. She isn't sharing her food and, suspecting her mysterious beauty is witchcraft, the priests have her arrested. Now well nourished, Bonne is virtually the only source of sustenance in the starving city. By feeding the townspeople, Bonne hopes to buy back the life of her patroness. Meanwhile, madness sweeps through Villeneuve, and Bonne befriends a host of outcasts during events that some choose to interpret as miracles and others as the work of the devil.

Told in three movements ("Rosary", "Labyrinth", "Danse Macabre",) Mirabilis is a phenomenal tale of miracles, magic, and madness.