characters in psychological and/or physical torment
"Ah, distincly I remember it was bleak December, and each seperate dying ember wrought its ghost upon the floor." (Poe 313) The setting is in a man's home, during winter and he's all alone.
While ravens speaking is not uncommon, the guy thinks it has a message and is sent by the devil or it may be an angel. ""Prophet!" said I, "things of evil!-prophet still, if bird or devil!-whether tempter sent, or whether tempest tossed thee here"