In the Alsace region of France, is a 1,300 year old abbey. In 2000, they started to notice that books were going missing, and had no idea how. Every night, they’d lock the doors, they started sealing the windows and posted guards at the doors. Things were still going missing.
They finally discovered that a young professor named Stanislas Gosse discovered a secret entrance and series of rooms, and was sneaking in nightly, to borrow old manuscripts.