"As I studied the floor I saw that a line of sticky footprints like the one on the body led away from the horror to the door. There was another blood-trail, too, and of a less easily explainable kind; a broadish, continuous line, as if marking the path of some huge snake. At first I concluded it must be due to something the murderer had dragged after him. Then, noting the way some of the footprints seemed to be superimposed on it, I was forced to believe that it could have been there when the murderer left. But what crawling entity could have been in that room with the victim and her assassin, leaving before the killer when the deed was done? As I asked myself this question I thought I heard fresh bursts of that faint, distant wailing.