TRUE NAMES by Vernor Vinge

data center, destroying much of Don’s higher reasoning centers before the other was even aware of her. Large, unclaimed processing units lay all about, and as DON and Erythrina continued their struggle, Mr. Slippery quietly absorbed everything in reach.
    Even now, DON could have won against either one of them alone, but when Mr. Slippery threw himself back into the battle, they had the advantage. DON.MAC sensed this too, and with a brazenness that was either mindless or genius, returned to his original appeal. “There is still time! The Mailman will still forgive you.”
    Mr. Slippery and Erythrina ripped at their enemy from both sides, disconnec.ting vast blocks of communications, processing and data resources. They denied the Mass Transmits to him, and one by one put the low-level satellites out of synch with his data accesses. DON was confined to land lines, tied into a single military net that stretched from Washington to Denver. He was flailing, randomly using whatever instruments of destruction were still available. All across the midsection of the US, silo missiles detonated, ABM lasers swept back and forth across the sky. The world had been stopped short by the beginning of their struggle, but the ending could tear it to pieces.

    The damage to Mr. Slippery and Erythrina was slight, the risk that the random strokes would seriously damage them small. They ignored occasional slashing losses and concentrated single-mindedly on dismantling DON.MAC. They discovered the object code for the simulator that was DON, and zeroed it. DON — or his creator — was clever and had planted many copies, and a new one awakened every time they destroyed the running copy. But as the minutes passed, the simulator found itself with less and less to work with. Now it was barely more than it had been back in the Coven.
    “
Fools!
The Mailman is your natural ally. The Feds will
kill
you! Don’t you underst —”
    The voice stopped in midshriek, as Erythrina zeroed the currently running simulator. No other took up the task. There was a silence, an … absence … throughout. Erythrina glanced at Mr. Slippery, and the two continued their search through the enemy’s territory. This data space was big, and there could be many more copies of DON hidden in it. But without the resources they presently held, the simulator could have no power. It was clear to both of them that no effective ambush could be hidden in these unmoving ruins.
    And they had complete copies of DON.MAC to study. It was easy to trace the exact extent of his infection of the system. The two moved systematically, changing what they found so that it would behave as its original programmers had intended. Their work was so thorough that the Feds might never realize just how extensively the Mailman and his henchman had infiltrated them, just how close he had come to total control. Most of the areas they searched were only slightly altered and required only small changes. But deep within the military net, there were hundreds of trillions of bytes of program that seemed to have no intelligible function yet were clearly connected with DON’s activities. It was apparently object code, but it was so huge and so ill organized that even they couldn’t decide if it was more than hash now. There was no possibility that it had any legitimate function; after a few moments’ consideration, they randomized it.
    At last it was over. Mr. Slippery and Erythrma stood alone. They controlled all connected processing facilities in near-Earth space. There was no place within that volume that any further enemies could be lurking. And there was no evidence that there had ever been interference from beyond.
    It was the first time since they had reached this level that they had been able to survey the world without fear. (He scarcely noticed the continuing, pitiful attempts of the American military to kill his real body.) Mr. Slippery looked around him, using all his millions of perceptors.