The Two Worlds by James P. Hogan Read Free Book Online

of electrically and gravitationally produced heat maintained large reservoirs of molten sulfur and sulfur compounds below the moon's surface, which eventually penetrated upward through faults to explode into the virtually zero-pressure of the outside. The result was a regular succession of spectacular volcanoes of solidifying sulfur and sulfur-dioxide frost that ejected at velocities of up to a thousand meters per second, and sometimes reached heights of 300 kilometers or more.

    Shannon was looking at a view of one of those volcanoes now, sent back from a probe on Io's surface. It had taken the mission's engineers and scientists more than a year of back-to-the-drawing-board experiences to devise an instrumentation package and shielding method that would function reliably under Jupiter's incessant bombardment of radiation, electrons, and ions, and Shannon had felt an obligation to be present in person to observe the results of their eventual success. Far from being the chore he had expected, the occasion had turned out an exhilaration and served as a reminder of how easy it was for supreme commanders of anything to allow themselves to become remote and lose touch with what was happening in the trenches. In future, he thought to himself, he would make a point of keeping more up to date on the progress of the mission's scientific projects.

    He remained in the command center discussing details of the probe for a full hour after he was officially off duty, and then at last excused himself and retired to his private quarters. After a shower and a change of clothes he sat down at the desk in his stateroom and interrogated the terminal for a listing of the day's mail. One item that had come in was qualified as a text message from Vic Hunt at Navcomms Headquarters. Shannon was both pleasantly surprised and intrigued. He had had many interesting talks with Hunt during the latter's stay on Ganymede, and didn't perceive him as being somebody with much time for idle socializing, which suggested that something interesting was afoot. Curious, he keyed in a command for Hunt's message to be displayed. Five minutes later he was still sitting there staring at the message, his brows knitted in a mystified frown. It read:

    Joe,

    To avoid any further cross words on this subject, I looked for some clues in the book you mentioned and came across some references on pages 5, 24, and 10. When you get down to sections 11 and 20, it all makes more sense.

    How they got 786 is still a puzzle.

    Regards

    Vic

    Not a word of it meant anything to him. He knew Hunt well enough to be reasonably sure that something serious was behind the message, and all he could think of was that Hunt was trying to tell him something highly confidential. But why would Hunt go to this kind of trouble when UNSA possessed a perfectly adequate system of security codes? Surely it wasn't possible that somebody could be eavesdropping on the UNSA net, somebody equipped with enough computer power to render its protective measures unreliable. On the other hand, Shannon reflected soberly, the Germans had thought exactly that in World War II, and the British, with their "Turing Engine" at Bletchley, had been able to read the complete radio traffic between Hitler and his generals, frequently even before the intended recipients. Certainly this message would mean nothing to any third party even though it had come through in plain English, which made it appear all the more innocuous. The problem was that it didn't mean anything to Shannon, either.
    * * *

    Shannon was still brooding about the message early the next morning when he sat down for breakfast in the senior officers' dining quarters. He liked to eat early, before the captain, the first navigation officer, and the others who were usually on early shift appeared. It gave him time to collect his thoughts for the day and keep up with events elsewhere by browsing through the Interplanetary Journal —a daily newspaper beamed out from