My choice would be Name Of The Rose. Sean Connery, a Catholic investigator, centuries ago, brings a Novice with him to investigate a murder at an Abby. It is soon established that the guarding of something in the library has lead to this crime. While investigating, Connery and his Novice become separated long enough for a young, mute maiden to drag the youngster into the shadows and teach him a thing or two.
The two eventually force their way into the library. A lantern is overturned, resulting in burning down the entire Abby.
With their work now finished, they mount their mules and head on to their next assignment. However, the young maiden meets the Novice at the roadside, and though she’s unable to speak he soon understands that she wants him to stay.
Connery continues on, never looking back, letting the Novice make his own choice. After a fierce internal battle with himself he turn away and hurries along to catch up.
But what if he’d stayed?