The door of number 13 opened suddenly and an arm came out. The arm was thin and covered in gray hairs. The fingernails were long and dirty.
Anderson shouted and pulled Jensen away from the door. The arm disappeared and the door closed. The sound of mad laughter came from number 13.
The landlord brought two men up the stairs. The men had axes in their hands. They swung their axes against the door of number 13.
Suddenly the men cried out and dropped their axes. They had hit a wall. The door of number 13 had disappeared.
In the morning, workmen pulled up the floor between rooms 12 and 14.
Under the floor they found a box. There were old papers inside the box. Anderson thought that the papers belonged to Nicolas Francken---- the man who had disappeared in 1560.
No one was able to read the writing on the papers. It was in a strange language. The writing was brown. The ink looked old. But Anderson did not think it was ink. He thought the papers were written in blood.