GGG Ping.
This reminds me of a movie where Sean Connery was a monk/investigator. The movie was called "Name of the Rose". It also had Christian Slater in it. In a nutshell, Sean Connery was the character, Brother William of Baskerville, that was sent to a monastery to investigate a strange murder. He discovers that the culprit of the murder was a book whose pages were poisoned (maybe the same type of arsenic?).