The rest of the Sky Room was filled with terraced banks of televisor panels, transmission boards, plotting tables, and various calculating machines, all visible from the central control table around which they crowded. One whole sector was devoted to other military installations and specialized headquarters in the Opal Cross. Other sectors linked the control table with field headquarters, observation centers, spacecraft, and so on. But now all the boards and tables, save the central one, were unoccupied. The calculating machines were untended and inoperative. And the massed rows of televisor panels were all blank gray--as pointless as a museum with empty cases. A similar effect of bewildered deflation was apparent in most of the faces of the World Executive Committee around the control table. The exceptions included Chairman Shielding, who looked very angry, though it was a grave anger and well under control; Conjerly and Tempelmar, completely and utterly impassive; Clawly, also impassive, but with the suggestion that it would only take a hairtrigger touch to release swift speech or action; and Firemoor, who, sitting beside Clawly, was plainly ill at ease--pale, nervous, and sweating. Shielding, on his feet, was explaining why the Sky Room had been cleared of its myriad operators and clerks. His voice was as cuttingly realistic as a spray of ice water. "... and then," he continued, "when astronomic photographs incontrovertibly proved that there were no alien craft of any sort near Mars--certainly none of the size reported and nothing remotely resembling a fleet, not even any faintly suspicious asteroids or cometary bodies--I hesitated no longer. On my own responsibility I sent out orders countermanding any and all defense preparations. That was half an hour ago." * * * * * One of the gray panels high in the Opal Cross sector came to life. As if through a window, a young man with a square face and crisply cropped blond hair peered out. The emptiness of the Sky Room seemed to startle him. He looked around for a moment, then switched to high amplification and called down to Shielding, "Physical Research Headquarters reporting. A slight variation in spatio-temporal constants has been noted in this immediate locality. The variation is of a highly technical nature, but the influence of unknown spy-beams or range-finding emanations is a possible, though unlikely, explanation." Shielding called sharply, "Didn't you receive the order countermanding all activities?" "Yes, but I thought--" "Sorry," called Shielding, "but the order applies to Research Headquarters as much as any others." "I see," said the young man and, with a vague nod, blanked out. There was no particular reaction to this dialogue, except that the studied composure of Conjerly and Tempelmar became, if anything, more marked--almost complacent.