Speaker for the Dead

Station, weeks before he would go back out into the forest. The piggies gave no sign that anything had changed; if anything, they were more open and friendly than before. No one ever spoke of Rooter, least of all Pipo and Libo. There were changes on the human side, however. Pipo and Libo never got more than a few steps away from each other when they were among them.
      The pain and remorse of that day drew Libo and Novinha to rely on each other even more, as though darkness bound them closer than light. The piggies now seemed dangerous and uncertain, just as human company had always been, and between Pipo and Libo there now hung the question of who was at fault, no matter how often each tried to reassure the other. So the only good and reliable thing in Libo's life was Novinha, and in Novinha's life, Libo.
      Even though Libo had a mother and siblings, and Pipo and Libo always went home to them, Novinha and Libo behaved as if the Zenador's Station were an island, with Pipo a loving but ever remote Prospero. Pipo wondered: Are the piggies like Ariel, leading the young lovers to happiness, or are they little Calibans, scarcely under control and chafing to do murder?
      After a few months, Rooter's death faded into memory, and their laughter returned, though it was never quite as carefree as before. By the time they were seventeen, Libo and Novinha were so sure of each other that they routinely talked of what they would do together five, ten, twenty years later. Pipo never bothered to ask them about their marriage plans. After all, he thought, they studied biology from morning to night. Eventually it would occur to them to explore stable and socially acceptable reproductive strategies. In the meantime, it was enough that they puzzled endlessly over when and how the piggies mated, considering that the males had no discernable reproductive organ. Their speculations on how the piggies combined genetic material invariably ended in jokes so lewd that it took all of Pipo's self-control to pretend not to find them amusing.
      So the Zenador's Station for those few short years was a place of true companionship for two brilliant young people who otherwise would have been condemned to cold solitude. It did not occur to any of them that the idyll would end abruptly, and forever, and under circumstances that would send a tremor throughout the Hundred Worlds.
      It was all so simple, so commonplace. Novinha was analyzing the genetic structure of the fly-infested reeds along the river, and realized that the same subcellular body that had caused the Descolada was present in the cells of the reed. She brought several other cell structures into the air over the computer terminal and rotated them. They all contained the Descolada agent.
      She called to Pipo, who was running through transcriptions of yesterday's visit to the piggies. The computer ran comparisons of every cell she had samples of. Regardless of cell function, regardless of the species it was taken from, every alien cell contained the Descolada body, and the computer declared them absolutely identical in chemical proportions.
      Novinha expected Pipo to nod, tell her it looked interesting, maybe come up with a hypothesis. Instead he sat down and ran the same test over, asking her questions about how the computer comparison operated, and then what the Descolada body actually did.
      "Mother and Father never figured out what triggered it, but the Descolada body releases this little protein-- well, pseudo-protein, I suppose-- and it attacks the genetic molecules, starting at one end and unzipping the two strands of the molecule right down the middle. That's why they called it the descolador-- it unglues the DNA in humans, too."
      "Show me what it does in alien cells."
      Novinha put the simulation in motion.
      "No, not just the genetic molecule-- the whole environment of the cell."
      "It's just in the nucleus," she said. She widened the field to include more variables. The computer took it more slowly, since it was considering millions of random arrangements of nuclear material every second. In the reed cell, as a genetic molecule came unglued, several large ambient proteins affixed themselves to the open strands. "In humans, the DNA tries to recombine, but random proteins insert themselves so that cell after cell goes crazy. Sometimes they go into mitosis, like cancer, and sometimes they die. What's most important is that in humans the Descolada bodies