In Umberto Eco's The Name of the Rose, William of Baskerville, a Franciscan monk, is sent to an abbey in the Apennines of Italy to negotiate for Pope John XXII with factions of monks who oppose the pope for his wealth and want to advocate living in poverty instead. When he arrives, he finds that Adelmo of Otranto, a monk who is the library's manuscript scholar, has died mysteriously and is next also commissioned to investigate Adelmo's death. The mystery grows more complicated as more monks die.
What William discovers is that Jorge of Burgos frequently leaves the monastery to travel the European countries in search of books to bring back to the monastery's library. One one occasion, Jorge returned with a rare copy of Aristotle's Poetics, in which Aristotle asserts his theories concerning drama, especially theories related to both comedy and tragedy. As a monk, Jorge believed laughter to be a "weakness, corruption, the foolishness of our flesh"; hence, in order to prevent anyone else from ever reading the book, he hid it deep in the library and locked it away (p. 474). He also poisoned the pages to further prevent anyone from reading it.
William further discovers that Adelmo got himself entangled in a sex scandal with Berengar of Arundel, the assistant librarian, just because Berengar so desperately wanted to see the book. Ridden with guilt, Adelmo committed suicide. In addition, since Jorge had poisoned the book's pages, both Berengar and Venantius of Salvermec, a manuscript translator, were killed by Jorge's poison.
Also, Malachi the librarian, was killed due to the poison because out of curiosity he as well read pages of the book.