After entering Government Reservation they went, not to the president's private quarters, but into the Treasury and down into the subbasement housing the most massive, the most utterly impregnable vault of the planet. There the nation's most responsible officers told Kinnison, with their entire minds as well as their tongues, what had happened. Upon that black day business had been suspended. No visitors of any sort had been permitted to enter the Reservation. No one had been allowed to approach the president except old and trusted officers about whose loyalty there could be no question. Airships and spaceships had filled the sky. Troops, armed with semiportables or manning fixed-mount heavy stuff, had covered the grounds. At five minutes before midnight Renwood, accompanied by four secret service men, had entered the vault, which was thereupon locked by the treasurer. All the cabinet members saw them go in, as did the attendant corps of specially-selected guards. Nevertheless, when the treasurer opened the vault at five minutes after midnight, the five men were gone. No trace of any one of them had been found from that time on. "And that--every word of it--is TRUE!" the assembled minds yelled as one, all unconsciously, into the mind of the Lensman. During all this telling Kinnison had been searching mind after mind; inspecting each minutely for the telltale marks of mental surgery. He found none. No hypnosis. This thing had happened, exactly as they told it. Now, convinced of that fact, his eyes clouded with foreboding, he sent out his sense of perception and studied the vault itself. Millimeter by cubic millimeter he scanned the innermost details of its massive structure--the concrete, the neo-carballoy, the steel, the heat-conductors and the closely-spaced gas cells. He traced the intricate wiring of the networks of alarms. Everything was sound. Everything functioned. Nothing had been disturbed. The sun of this system, although rather on the small side, was intensely hot; this planet, Four, was a long way out. Pretty close to Cardynge's limit ... or the Boskonians had improved their technique--tightened up their controls. A tube, of course ... for all the tea in China it had to be a tube. Kinnison sagged; for the first time in his life the indomitable Gray Lensman showed his years and more. "I know that it happened." His voice was grim, quiet, as he spoke to the still protesting men. "I also know how it was done, but that's all." "HOW?" they demanded, practically in one voice. "A hyperspatial tube," and Kinnison went on to explain, as well as he could, the functioning of a thing which could not be grasped intrinsically by any nonmathematical three-dimensional mind. "But what can we or you or anybody else _do_ about it?" the treasurer asked, numbly.