"What was the whole of your case against Penreath but a series of inferences?" retorted Colwyn. "Circumstantial evidence, and the circumstances on which you depended in this case, were never fully established. Furthermore, your facts were not consistent with your original hypothesis, and had to be altered when the case went to trial. Now that I have discovered other facts and inferences which are consistent with another hypothesis, you strive to shut your eyes to them, or draw wrong conclusions from them. Your suggestion that Penreath must have hidden the money in the pit because he was arrested near it is a choice example of false deduction based on the wrong premise that Penreath hid the money there on the night of the murder. He could not have done so because he had no rope, and how was he, a stranger to the place, to know that the inside of the pit was covered with creeping plants of sufficient strength to bear a man's weight? The choice of the pit as a hiding place for the money argues an intimate local knowledge." "You have not yet told us how you came to deduce that the money was in the pit," said Mr. Cromering, who had been examining the pocket-book and money. "While I was examining the mouth of the pit the previous afternoon I found this piece of paper at the brink, trodden into the clay. Later on I recognised the peculiar watermark of waving lines as the Government watermark in the first issue of Treasury war notes. From that I deduced that the money was hidden in the pit. It was all in Treasury notes, as you see." "I'm afraid I don't quite follow you now," said the chief constable, with a puzzled glance at the piece of dirty paper in his hand. "This piece of paper is not a Treasury note." "Not now, perhaps, but it was once," said the detective with a smile. "It puzzled me at first. I could not account for the Treasury watermark, designed to prevent forgery of the notes, appearing on a piece of blank paper. Then it came to me. The first issue of Treasury notes were very badly printed. Ordinary black ink was used, which would disappear if the note was immersed in water. It was an official at Somerset House who told me this. He informed me that they had several cases of munition workers who, after being paid in Treasury notes, had put them into the pockets of their overalls, and forgotten about them until the overalls came back from the wash with every vestige of printing washed out from the notes, leaving nothing but the watermarks. It occurred to me that the same thing had happened in this case. The murderer, when about to descend to the pit to conceal the money, had accidentally dropped a note and trodden it underfoot, and it had lain out in the open exposed to heavy rains and dew until every scrap of printing was obliterated."