"I should think it was," Guest answered. "You should see the pictures that come on the screen when he is thinking of Marjorie Poole!" Gouldesbrough started. "How do you mean?" he said. "Well," Guest replied, turning off the blue flame of the Bunsen burner, and stirring the mixture in the test-tube with a glass rod--"well, Marjorie Poole's a pretty girl, but when this man calls her up in his memory, she's a sort of angel. You know what a difficulty we had when we got over the Lithium lines in the ash of the muscular tissue of the blood, which had to be translated through the new spectroscope into actual colour upon the screen? Well, we did get over it, but when the subject thinks of Marjorie Poole, the colour all fades out of the picture, the actual primary colours, I mean. The girl flashes out into the dark in white light, like a sort of angel! and the first time I saw it I jumped up from my chair, shut off the connecting switch and turned up the lamps. It was so unlike any of the other pictures we have ever got, and for a moment I thought I had been over-doing it a little in the whisky line." Gouldesbrough stopped the strange inhuman creature in his unholy amusement. "Well, I'm going to bed now," he said. "We'll begin work to-morrow. I saw some supper put out for me in the study." "Right oh," Guest answered. "Good-night then, William. I'm going to take the beef broth and phosphates to our Brain down below in the cell." CHAPTER XII THE TOMB-BOUND MAN Mr. Guest had visited his victim and had gone. Supper was over. Beef-tea and phosphorous! and Mr. Guest had said his mocking words of good-night. "Sleep well, Mr. Rathbone! I shall not be compelled to ask you to wear that pretty metal cap until to-morrow, so I won't turn out the light. You have a book to read, you've had your supper, and I wish you a pleasant time alone. No doubt you will occupy your leisure in thinking of Miss Marjorie Poole. You'll recall that occasion in a certain room hung with pink, when you kissed her by the side of the piano in the white and gold case! I know you often recall that happy incident." He had closed the heavy steel door with a last chuckle of malice and power, leaving the prisoner white and shaking with fear. How did this sinister and devilish gaoler know his intimate thoughts? He groaned deeply, and then, as he had done a thousand times before, gazed round the place in which he was in terror-struck amazement. Where was he? _What_ was this horrible prison with all its strange contrivances, its inexplicable mysteries?