The major hung up his receiver. The room seemed to be much lighter now. The radium glowed more brightly, and the scintillations on the wall behind had increased in intensity. He advanced towards the radium, and was immediately conscious that his discomfort increased. There was a smarting sensation on the front of his body, as if it were exposed to fire. His breathing became more difficult, his headache increased. He drew back to the wall, and the symptoms became less marked. The bell rang again. "I ought to inform you, Smithers," said the voice, "that no good at all would result from your attempting to destroy the radium. As a matter of fact, if you broke or crushed it you would feel very much worse. The particles would fly all over, and you would inhale them. The symptoms would be intensely interesting if you would care to experience them, but I won't answer for the consequences. I just want you to understand that you can't possibly escape from this important new element when once you are imprisoned in a room with it, especially when the room is only twelve feet square." The major did not reply. He hung up his receiver in silence. At the other end of the telephone was Robert Blyth, F.R.S., D.Sc., etc., etc., a little red-haired man, whose researches on the Mutilation and Redintegration of Crystals are of world-renown. He was a grave little man as a rule. Only when on the verge of some discovery, or when watching the successful progress of an experiment, did he wax cheerful. He did this now as he surveyed his notes of the report of John Smithers, a horse-soldier, in durance vile in the adjoining room. "Pulse, 73; temperature, 99; heart, irregular. Good. Respiration difficult. Well, that's understandable. He's been in there thirty-one minutes. Thanks to a strong constitution, he's scarcely felt anything yet; but now he'll have trouble. John Smithers, you are going to have an exceedingly bad time of it. If you weren't a criminal I should hesitate in giving it you. As it is, you must suffer for the cause of science. Your experience will, no doubt, make you hesitate before you attempt another crime." The professor tilted back his chair. "Strange," he mused, "how brain controls matter to the end. Here's John Smithers in the next room--a strong man admittedly--cribbed, cabined, and confined by a man he could probably crumple up with one hand. It was a stroke of genius to advertise my discovery in the papers. The criminal classes all read them now, and I thought I should probably attract a thief. I placed the radium in the middle of the room, and painted the wall behind with sulphide of zinc so that he couldn't possibly miss it. I easily constructed a threshold that closed the door when stepped upon. And then I had only to wait." Here the bell rang. "Aha, Smithers, you are growing impatient. Well?" "Are you a Christian?" came the reply. "I hope so. Why?"