Receiving the invitation telegram from some mysterious baron, you as journalist specialized in occult sciences have agreed to visit his manor. At first glance, his residence seems absolutely uninhabited, but searching room by room you'll find some items: a crucifix, flasks, a key, a revolver, a dirk, etc. It seems that here is somebody to fight.
The gameplay includes walking around the manor (left, right, forward, and turn round) and choosing the actions such as search the rooms for useful items during some amount of time, use these items, read, and fight with the creatures inhabited the manor such as bats, rats, cobras, fanatics, etc. Attacking you, monsters take down your potential and mental health until you will be moved to the manor's cemetery. So you have to survive for certain period of time until midnight. Also you have to search for the clues such as secret codes to solve the mystery around the baron and his manor, finally find and burn the pentagram.