Northern Italy, 1327. The Franciscan monk William of Baskerville and his young apprentice Adso of Melk reach an isolated Benedictine abbey on the Alps to aid in a dispute between the Franciscan Order and the Avignon papacy. Upon arrival at the abbey, the two find themselves involved in a chain of mysterious deaths.

Mima Taro is a writer who has hit a slump. Tired of city life, he moves into the house he inherited from his father in the mountainous Hayabusa. When he joins the fire brigade, he becomes involved in a series of arson cases and suspicious incidents. As Taro searches for the truth, a huge conspiracy comes to the surface.