The haunting in this instance is inventive and effectively creepy. The hotel in which Anderson is staying has no room number 13, apparently a traditional omission in Danish hotels. But after dark, a room number 13 appears. Anderson is in room number 12, and at first does not notice the presence of the new room. He accidentally tries its door, and it makes his own room smaller when it is there. Even the landlord is not aware of it. Initially, room 13 is presented as a puzzle rather than a threat. It is only on the third night that it becomes frightening.