As though in response, the visa-phone hummed, and its screen glowed. The image formed was a young officer, an officer with a wisp of blond mustache and a pale face forced into disciplined blankness by a straining will. * * * * * Some of the weariness left the younger man's haunted eyes as he saluted Captain McPartland. He spoke, his lips moving rapidly, but the words were gibberish. "Radio, scramble for ship code," Lieutenant-Commander Clemens said into the intra-ship. He turned to the Captain. "I hope they have the right code, Sir." "--extreme emergency, Sir," came the voice of the officer from Mars Base. "Deemed it advisable to use code." "Very commendable, Mister," McPartland acknowledged, tersely. "My compliments to the Admiral, and may I speak to him at once." "I'm sorry, Sir," said the other, "the Admiral is at Terra Base with the major fleet units. I am Lieutenant Browne, commanding." "Commanding!" exploded Jon. "Then the base must be almost empty!" "There is only a maintenance crew here," admitted the Lieutenant wearily, and added defensively, "It's the same at Jupiter Base, Sir. "All ranking officers are at Terra Base with the battleships, to receive instruction in the use of new equipment the Specialists have perfected--You know, Captain, defense against mono-charge rays." "Yes," groaned McPartland, "I know. The Specialists strip our Bases to make a big ceremony--of the only thing they've done for the Patrol in decades. And now--" He squared his broad shoulders, biting back the rest. "I have an urgent report. Who is ranking officer outside of Terra?" "You are, Sir. I was about to radio you, when your call came through." Browne saluted again and drew himself up rigidly, as he went on: "I beg to report, Captain, that we have lost radio contact with Terra Base. Telescopic observation reveals--" his voice faltered and the lines worked more deeply into his white face--"reveals, Sir, _no trace_ of Terra, Luna, or the stars and planets normally visible--throughout a spherical area six-hundred-thousand miles in diameter." The Lieutenant paused. McPartland said nothing. His square jaw was straining, as though to knot his face into the same hard fist as each of his great hands. On the face of Engineer McTavish, the eager smile had frozen. Ray Control Officer Reynolds let his restless fingers fall motionless on the table before him. Clemens' small, regular features were swept blank by an apprehension too intense to be mirrored. All of them strained to hear Browne's concluding words, in a voice that was suddenly a whisper: "Within that area is an absolute blackness we cannot penetrate by radio, radar, or telescope!" "Thank you, Mister," the Captain acknowledged, "that checks with our own observation." He was not aware of his own voice, the cold, slow words could have been spoken by some one else. "Have you contacted Jupiter Base?" "Yes, Sir," Lieutenant Browne answered eagerly, "they too agree."