I have already recorded many of the adventures of my friend Martin Hewitt, but among them there have been more of a certain few which were discovered to be related together in a very extraordinary manner; and it is to these that I am now at liberty to address myself. There may have been others—cases which gave no indication of their connection with these; some of them indeed I may have told without a suspicion of their connection with the Red Triangle; but the first in which that singular accompaniment became apparent was the matter of Samuel's diamonds. The case exhibited many interesting features, and I was very anxious to report it, with perhaps even less delay than I had thought judicious in other cases; but Hewitt restrained me.
"No, Brett," he said, "there is more to come of this. This particular case is over, it is true, but there is much behind. I've an idea that I shall see that Red Triangle again. I may, or, of course, I may not; but there is deep work going on—very deep work, and whether we see more of it or not, I must keep prepared. I can't afford to throw a single card upon the table. So, as many notes as you please, Brett, for future reference; but no publication yet—none of your journalism!"
Hewitt was right. It was not so long before we heard more of the Red Triangle, and after that more, though the true connection of some of the cases with the mysterious symbol and the meaning of the symbol itself remained for a time undiscovered. But at last Hewitt was able to unmask the hideous secret, and for ever put an end to the evil influence that gathered about the sign; and now there remains no reason why the full story should not be told....