“In the case of Mr. Colburn I adopted quite a different method. I had become a customer of his, and had encouraged his son to confide in me. From him I gradually learnt his father’s habits and peculiarities, particularly that of smoking a pipe in the shop after lunch, and, when he had finished it, of refilling it and putting it away on a shelf. I examined the pipe in young Colburn’s absence, and noticed that it was cracked. That evening, I visited a tobacconist at some distance from here and bought a pipe of similar make and shape.
“Within a few days, as I had expected, I saw Mr. Colburn enter Copperdock’s shop. It was a fair assumption that he had gone in to buy a new pipe to replace the old one, since I had learnt that his tobacco was always delivered to him. I took a very small splinter of glass, covered it with a preparation which Dr. Morlandson had given me, and drove one end of it into a notch I had made in the mouthpiece of the pipe I had bought. I then went to Colburn’s shop, on an errand which necessitated young Colburn’s going to the bakehouse and leaving me alone. I saw, as I had expected, a new pipe lying filled on the shelf. I substituted mine for it, put Mr. Colburn’s pipe in my pocket, waited until young Colburn came back with my purchase, and left the shop. I was in the country when Mr. Colburn died, but I heard the details later, as no doubt you have heard them, Dr. Priestley.”
“Yes, the deaths of Colburn and Martin strengthened my theory that Dr. Morlandson was at the bottom of the affair,” replied the Professor calmly. “I guessed that there was extensive medical knowledge behind both of them.” His one idea was to prolong this recital as much as possible.
“You will agree, however, that it would have been impossible to trace Mr. Colburn’s death to me. By this time I had come to the conclusion that it would be as well to stage the scene of my executions as far as possible in Praed Street. I wished to concentrate attention upon this particular district, since I knew that the obvious effect on the police would be to suggest to them an inhabitant of it. As soon as they did this, I was ready to supply a number of hints and inferences. I was thus able to become on confidential terms with Whyland, and, by making a friend of him, to put myself above suspicion. And all the time I was influencing his mind in the direction of Mr. Copperdock. It was a most interesting psychological study, I can assure you.
“Pargent, whom I determined to tackle next, presented an entirely different problem. He lived some distance from Praed Street, and though I might have devised some means of killing him in his own home, I was most anxious to adhere to the rule I had laid down. It was not until I had carefully considered his habits that I saw my way clear. During the years which I had spent observing my victims, I had discovered the regularity of his visits to his sister at West Laverhurst. And in this regularity I saw my opportunity.
“One Saturday morning, when he was due to go to West Laverhurst, I went down from Waterloo to Penderworth, for which the station is Wokingham, ostensibly to collect plants. I went to Waterloo by way of Paddington and the tube, the most obvious way of getting there. But at Paddington I called at the booking-office, and took a ticket to Reading. Having arrived at Penderworth, I made myself as conspicuous as possible at the inn, in the character of Mr. Ludgrove, and then went out with a suit-case, with the declared intention of collecting plants. In the suit-case were my dyes and paints, also a change of clothing.
“Now, Penderworth is four miles from Reading, where the train stopped by which Pargent habitually returned home. I found a convenient coppice, in which I got myself up as a man with iron grey beard and hair, and a conspicuous mark upon my face. I left my suit-case in the coppice, carefully hidden, and in it Mr. Ludgrove’s clothes and spectacles. Then I walked to Reading and caught the train in which Pargent was travelling. On our arrival at Paddington I followed him through the station, and was by his side when he made his dash across Praed Street to catch the bus. My opportunity came on the refuge, and I employed the same method as I had done in the case of Tovey.
“I had ascertained that a train left for Reading ten minutes after the arrival of the train by which I had travelled up. I had just time to catch this—I already had the ticket which I had purchased in the morning. As the train neared Reading, I went to the lavatory and removed the dye and paint. From here I stepped out on to the platform and passed the barrier unremarked. Even had I been noticed in London, and my description circulated, I thus ran very little risk. The most noticeable thing had been the ‘port-wine mark,’ and this of course had vanished. I walked to the coppice, buried the clothes I was wearing, resumed the apparel of Mr. Ludgrove, and returned to the inn with my suit-case full of the first plants I could lay my hands on. I had apparently an excellent alibi.
“With the death of Pargent, the curious coincidence that all three victims had received counters came to light, as I had anticipated it would. I thought it wise to suspend my operations for a while, while I prepared my plans for dealing with the remainder of the surviving jurymen. Goodwin presented the greatest puzzle. He was confined to his house, almost to one room, and I despaired of being able to reach him. I had nearly decided to leave him alone, knowing that his death could not be delayed very long in any case. But I had a sudden inspiration. The numbered counters had attracted a good deal of attention, and the sequel to their receipt was well known. It was quite possible that Goodwin, to whom any shock was likely to be fatal, would die as the mere result of finding one in his post. I made the experiment, and it was successful. But I claim no great credit for this exploit. I might well have failed, had fortune not favoured me, and I was compelled to abandon Praed Street as the scene of his death. I have always considered that the execution of Goodwin was not up to my usual standard.
“But I have omitted the case of Martin, upon which I rather pride myself. Put yourself in my position, Dr. Priestley. Here was a man, living in the suburbs, and having an office in the City. How was I to lure him to Praed Street, and ensure his death when he arrived there, at a time when Praed Street had already gained notoriety as the scene of three mysterious deaths? I knew quite a lot about Martin, more than most people, in fact. I knew that he had once been in business in Praed Street, and that he had prospered there rather more rapidly than his apparent business warranted. My connection among the shadier classes in the neighbourhood helped me there. I discovered, hint by hint, that he was a well-known fence, a receiver of stolen goods, that is, Dr. Priestley, and that discovery, coupled with the fact that the premises he had once occupied were again changing hands, gave me an idea.