But Colwyn had never allowed himself to be swayed too much by circumstance. Appearances were not always a safe guide in the complicated tangle of human affairs. Things were forever happening which left experience wide-eyed with astonishment. The contradictions of human nature persisted in all human acts. In this moat-house mystery, the grimmest paradox of his brilliant career, Colwyn was determined not to accept the presumption of the facts until he had satisfied himself that no other interpretation was possible. His subtle mind had been challenged by a finger-post of doubt in the written evidence; a finger-post so faint as to be passed unnoticed by other eyes, but sufficiently warning to his clearer vision to cause him to pause midway in the broad track of circumstantial evidence and look around him for a concealed path. It was the point he had mentioned to Caldew at his chambers after reading the copy of the coroner's depositions which Merrington had lent him. While perusing them he had been struck by a curious fact. The medical evidence stated that the cause of death was a small punctured wound not larger than a threepenny piece, but added the information that the hole in the gown of the dead woman was much larger, about the diameter of a half-crown. The Government pathologist had formed the opinion that the revolver must have been held very close to the body to account for the larger scorched hole. That inference was obvious, but Colwyn saw more in the two holes than that. It seemed to him that the live ring of flame caused by the close-range shot must have been extinguished by the murderer, or it would have continued to smoulder and expand in an ever-widening circle. And that thought led to another of much greater significance. The shot had been fired at close range to ensure accuracy of aim or deaden the sound of the report. But, whichever the murderer's intention, the second purpose had been achieved, intentionally or unintentionally. How had it happened, then, that the sound of the report had penetrated so loudly downstairs? As Colwyn moved about the room, examining everything with his quick appraising eye, he noticed that the position of the bed had been changed since he last saw it. The head was a trifle askew, and nearer to the side of the wall than the foot. The difference was slight, but Colwyn could see a portion of the fireplace which had not been visible before. The bed stood almost in the centre of the room, the foot in line with the door, and the head about three or four feet from the chimney-piece. In noting this rather unusual position during his last visit, Colwyn had formed the conclusion that it had been chosen for the benefit of fresh air and light during the summer months, as the window, which looked over the terraced gardens, was nearer that end of the room.