The one point which perplexed Colwyn was the successful concealment of the pistol on the night of the murder. That part of the plan was as essential to the murderer as the false report, but it seemed strange that the pistol had not been discovered when the room was searched. An examination of the grate upstairs might reveal the reason. Before leaving the gun-room Colwyn replaced one of the pistols and restored the case as he had found it to its original position. He carried away with him the pistol which had been used. When he reached the upstairs bedroom he locked the door before proceeding to examine the fireplace. It was immediately apparent to him that the pistol had not been placed in the grate or beneath it. Either place would have meant discovery when the room was searched. It was a careful examination of the upper portion of the grate which suggested the hiding-place. The weapon could have been safely hidden within the broad iron flange running round the open damper of the grate. The complete revelation of this portion of the murderer's design came to Colwyn as he was passing his hand over the inner surface of this ledge. It was a register grate, and the space at the back had not been filled in. The murderer, when concealing the pistol at the top of the grate, had only to balance it carefully on the flange, with the muzzle pointing into the room, to ensure that the recoil from the report would cause the weapon to fall into the deep hole between the back of the grate and the chimney. This additional proof of the murderer's perverted intelligence impressed Colwyn as much as the mechanism for the false report. The pistol, blindly recoiling and jumping behind the grate after the explosion of the blank charge, was almost as effectually concealed as at the bottom of the sea, and might have remained there for years without discovery. Colwyn plunged his arm into the hole, but could not reach the bottom. But the murderer had more in his mind than the effectual concealment of the pistol, important though that was to him. The grate was an excellent choice for two other reasons. It carried the slight vapour from the tinder wick up the chimney, and the convex iron interior formed an excellent sounding board which would enhance the sound of the report. Truly the dark being who had planned it all had left nothing to chance. He had foreseen everything. His handiwork bore the stamp of unholy genius.