Bernard Gui thinks the case is closed, but William doubts it; the abbot wants William to leave; Adso and William enter the library again, where they find the answers to all their questions but in the end face a much bigger catastrophe.

Bernard Gui demands imprisonment of the monk he thinks is guilty; Adso begs William for help; under Bernard Gui's command, a trial against Remigio begins and he is betrayed by a friend; Anna manages to enter the abbey and find the prisoners.

William speaks before the council when monks find the next victim; Remigio and Anna meet at the cemetery; Adso finds out that the red-haired girl was captured and puts himself at risk to save her; William loses an important clue.

The delegations argue about the wealth of the church; Remigio can't hide his past any longer but escapes Bernard Gui with the help of William and Adso; the debate begins with a shocking revelation by the cardinal; Adso confesses to William.

William and Adso solve the riddle in the library and continue their search for clues; Adso visits the girl; while the monks mourn the victim of another incident, the monks of the order of St. Francis and the papal delegation arrive at the abbey.

In desperate search for glasses, William gathers more clues and is able to decipher a secret message; Adso upsets the monks by researching Dolcino and Jorge warns him against women; in the mountains, a woman named Anna swears revenge on Bernard Gui.

After another tragic incident, William and Adso suspect a dark secret and try to enter the library; Adso befriends a girl with red hair in the woods; Remigio reflects his past; the papal delegation heads to the abbey.

William of Baskerville and his novice, Adso, arrive at a secluded abbey, where a debate about crucial beliefs is about to take place; the abbot asks William to investigate the death of a young monk, but not everyone supports the search for the truth.