Braveheart - Prison Door Open and Closes
This takes place near the end of the movie, when William Wallace has been captured and thrown in jail. Princess Isabelle then decides to pay him a visit and they talk for a few minutes. She is let in by a prison guard, who leaves the room soon after she enters.
During this scene if you look at the door to the prison cell, which the prison guard leaves a bit open, you will notice that it's open widely in some shots and that it's almost closed in other shots even though no-one touches the door in between. In one of the shots the shadow of the prison guard can be seen but it disappears shortly after.