Ghost Stories of an Antiquary #2

While researching documents in Viborg, Anderson stays at a hotel in room 12. At night, he sees a room numbered '13' adjacent to his but he can't find it by daylight. Within the room, Anderson keeps hearing weird noises and sees frightening shadows reflected from the windows. When the man in room 14 finally confronts Anderson to complain about the noise they confront room 13 and see a terrifying creature within.