Mayes never recovered consciousness, and was dead when we visited the hospital the day after; both skull and spine were badly fractured. And the very last we saw of the Red Triangle was the implement with which it had been impressed, which was found in his pocket.

It was a small triangular prism of what I believe is called soapstone. It was perhaps four inches long, and the face at the end corresponded with the mark that Hewitt had seen on the forehead of Mr. Jacob Mason. It fitted closely in a leather case, in the end of which was a small, square metal box full of the red, greasy pigment with which the mark had been impressed.

It was from Broady Sims that we learnt the exact use and meaning of this implement: though he would not say a word till he had seen with his own eyes Mayes lying dead in the mortuary. Then he gasped his relief and said, “That’s the end of something worse than slavery for me! I’ll turn straight after this.”

Sims’s story was long, and it went over ground that concerns none of Hewitt’s adventures. But what we learned from it was briefly this. It had been Mayes’s way to meet clever criminals as they left gaol after a term of imprisonment. In this manner he had met Sims. He had made great promises, had spoken of great ideas which they could put into execution together, had lent him money, and then at last had “initiated” him, as he called it. He had put him to lie back in a chair and had directed his gaze on the Red Triangle held in the air before him: and then the Triangle had descended gently, and he felt sleepy, till at the cold touch of the thing on his forehead his senses had gone. This was done more than once, and in the end the victim found that Mayes had only to raise the Triangle before him to send him to sleep instantly. Then he found that he must do certain things, whether he wanted or not. And it ended in complete subservience; so that Mayes could set him to perpetrate a robbery and then appropriate the proceeds for himself, for by post-hypnotic suggestion he could force him to bring and hand over every penny. More, the poor wretch was held in constant terror, for he knew that his very life depended on the lift of his master’s hand. He could be sent into lethargy by a gesture and killed in that state. That very thing was done, in fact, as we have seen, in two cases.

Sims was but one of a gang of such criminals, brought to heel and made victims. Their minds and souls, such as they were, had passed into the miscreant’s keeping, and terror reinforced the power of hypnotism. They committed crimes, and when they failed they took the punishment; when they succeeded Mayes took the gains, or at any rate the greater part of them. He went, also, among people who were not yet criminals, and by degrees made them so, to his own profit. The case of Henning, the correspondence clerk, was one that had come under Hewitt’s eyes. He used his faculty also with great cunning in other ways — as we had seen in the matter of the Admiralty code. And it was even said among the gang that a man he had once hypnotised he could force by suggestion to commit suicide when he became useless or inconvenient.

Sims and the ragged fellow who had decoyed me into Mayes’s den were the only members of the gang whom we could identify after his death, but many others must have shared their relief; and I sincerely hope — though I hardly expect — that they all availed themselves of their liberty to abandon their evil courses. As in fact the two I speak of did, and took to honest work.

All that had remained mysterious in the earlier cases now became clear. In the first, the case of Samuel’s diamonds, Denson had been put into the office where Samuel had found him, by Mayes, with the express design of effectin............