Källare [The Cellar]

We have finally found a location where we can build new escape rooms! However, on the premises, there is a door that nobody seems to have a key to, and we are unable to break into the room. We investigate the matter, and find an old blueprint of the space. There should be a large cellar behind the door. We investigate the matter further, and find out that the previous tenants on our premises were a business that conducted paranormal investigations. One of the owners of that business had disappeared years ago. We contact the other owner, who does have a key to the cellar. We get in and start planning a new escape room, but the space feels really creepy. The employees planning for the new escape room hear strange sounds, out of the corner of their eyes they see objects moving, and they experience various unexplainable physical and mental symptoms… What on earth is going on in the Cellar?