"I think I can reconstruct the thing from the first," Wade said, "though some of the secret died with Grantham here. You told me yourself that he and Gray had long been prevented from engaging in the lines of research they desired because of their lack of funds. Well, I think that Grantham grew resentful at this, and then determined, and that he and Gray resolved to lay hands on the money they needed in their own fashion. To do it they worked out an elaborate and incredibly ingenious plan, that hinged upon Grantham's known reputation as a great physicist. "Grantham and Gray prepared the tourmaline-crystal set-up, and then let it be known in one way or another that Grantham had discovered a method of making things invisible. Of course there was excitement, and of course the reporters, Carton among them, rushed out here to learn all about it. Then Grantham reluctantly consented to a demonstration, and after pulling this tourmaline-crystal stunt, sent them away, and you too, perfectly convinced that he had actually found a way to make matter invisible. That was his first great step--to implant in the minds of reputable witnesses the absolute conviction that he had really the power of making things invisible. "Just what happened on that afternoon between Grantham and Gray may never be known fully, but there seems little doubt that Gray, who had been sullen at the demonstration that morning, had come to the point where he had resolved not to go on with the scheme. Probably he threatened to expose Grantham if he did not stop it, and no doubt Grantham saw exposure and oblivion on the way. Fearing Gray's confession, he killed him, and disposed of his body here in the laboratory. He had the knowledge to do that, and I've found that on that afternoon he received from the supply-rooms here an inordinate order of acids which were without doubt used in the disposition of Gray's body. However it was done, there is not the slightest doubt that on that afternoon Gray, and even his body, passed out of existence in this laboratory.