"Of course I did; but what is the meaning of it?"

"The Tuan told me I was a fool, and that no man committed a crime in this country without leaving some trace of it; also that the Tuan would prove this to me by investigating the next case himself. I am a Malay, Tuan, and do not like to be called names when I have not deserved them. I knew that crimes were often committed and no trace left, so I thought I would prove this to the Tuan. Did I leave any traces?"

"No, you certainly did not."

"But if the Tuan had only thought, he must have known these were not real burglaries; they were all exactly alike, even to the article stolen. Has the Tuan ever known such a thing happen before? Even the letter did not help him. Surely no thief gives himself away—in this country, at least! I was quite prepared for the Tuan to tell me he saw the whole thing when he got the letter. He must have forgotten how he spoke to me."

Cassim was evidently a reader of character and knew how I would take his rebuke, which I had undoubtedly fully deserved.

"You are right and I was wrong, Cassim," I said; "I am sorry I spoke as I did. But you were doing a very risky thing. Suppose Tuan Barton, or the Tuan Doctor, or the Tuan Besar (the Resident) had caught you in their houses?"

"Who would have suspected or said anything to me? I am the detective-sergeant, and if I find a house open at night it is my duty to investigate the matter. I was seen, but the Tuan never thought of asking even that. If he had asked the Sikh sentry at the Residency, he would have said he had seen me walk round the building, for he challenged me. Why did the Tuan forget such a simple inquiry?"

"Of course, no one knows anything of this?" I said, evading his last question.

"Surely the Tuan can trust me?" he replied.

"All right. Keep it to yourself. I am much obliged to you for the lesson, and in future we will work together. Produce the clocks, and make up any story you like as to how you found them. The thief, of course, must have cleared out, and these burglaries must go in the crime book as 'Undetected: property recovered.' Oh, I forgot. How did you manage to open the doors?"