"I should have to see the pin," said Stone, "before drawing any conclusion from it. You did not examine it closely, you say?"
I had not said so, but I suppose he deduced it from my slight knowledge of its characteristics.
"I did not examine it through a microscope," I replied.
"You should have done so. If it were really a broken hat-pin, it would show a clean, bright break at the end; whereas, were it a shorter pin which had lost its head, it would show at the end a fraction of an inch of duller steel, and perhaps an irregular surface where the head had been attached."
"I can see that you are right, but I cannot see why it should make much difference which it was."
"My dear sir, according to your statement, the only clue we have to work upon is the weapon which was used. The weapon is always an important item, if not the most important, and it cannot be scrutinized too closely or examined too minutely, for, sooner or later, it is almost always certain to expose the criminal."
"I had thought," I said humbly, "that I possessed a degree of detective instinct, but I now see I was mistaken. I assumed the pin to be a hat-pin, and thought no more about it."
"It may be one," said Stone, "and the only way to find out is to see it. Of course I must also examine the apartment, and then, if necessary, question some of the parties concerned. But at this moment I have little doubt in my mind as to who killed Robert Pembroke. I will take the case, because, though unusual, it promises to be a short one. I think I may safely say that by to-morrow night at this hour we will not only have discovered the criminal, but obtained a confession. But I will say the criminal has been very, very clever. In fact, I think I should never have conceived of such various kinds of cleverness combined in one crime. But, as is often the case, he has outwitted himself. His very cleverness is his undoing."
Surely the man was a wizard! I looked at him without a word after he had made his astounding announcement. I had no idea whom he suspected, but I knew he would not tell me if I asked, so I thought best to express no curiosity, but to leave the matter in his hands, and await his further pleasure.