I can only remember one scene: A old man with a white beard (some kind of wizard, maybe?) and a younger man are in a room. There’s a mirror in the room that has a woman trapped in it. The mirror is hanging on a nail, but is slowly slipping off.
The old man notices the mirror slipping and shouts “Do not let the mirror break!” or something of that nature. Of course the mirror falls and breaks and the woman is released – at which point she strides over to the old man and chokes him to death.
If I had to guess this movie probably came out in the 80s or 90s.
Was this by chance a fantasy movie? There are several movies about souls or spirits trapped in mirrors, but when I read your description, I’m picturing this dark misty swamp like scene going up into some sort of tower through a window and seeing the scene you describe above play out. Almost like a sinister fairytale type movie maybe?