"For that reason, the body has to learn how to scavenge selectively. In human beings, that lesson isn't learned completely until about a month after birth. During the intervening time, the newborn infant is protected by antibodies that it gets from the colestrum, the 'first milk' it gets from the breast during the three or four days immediately after birth. It can't generate its own; it isn't allowed to, so to speak, until it's learned the trick of cleaning up body residues _without_ triggering the antibody mechanisms. Any dead cells marked 'personal' have to be dealt with some other way." "That seems clear enough," Hamelin said. "But I don't see its relevance." "Well, we're in a position now where that differentiation between the self and everything outside the body doesn't do us any good any more. These mutated bacteria have been 'selfed' by the mutation. In other words, some of their protein molecules, probably desoxyribonucleic acid molecules, carry configurations or 'recognition-units' identical with those of our body cells, so that the body can't tell one from another." "But what has all this to do with re-education?" "Just this," Carson said. "What we do here is to impose upon the cells of the body--all of them--a new set of recognition-units for the guidance of the lymph nodes and the spleen, which are the organs that produce antibodies. The new units are highly complex, and the chances of their being duplicated by bacterial evolution, even under forced draught, are too small to worry about. That's what Re-Education is. In a few moments, if you like, we'll show you just how it's done." Hamelin ground out his fifth cigarette in Mudgett's ashtray and placed the tips of his fingers together thoughtfully. Carson wondered just how much of the concept of recognition-marking the under-secretary had absorbed. It had to be admitted that he was astonishingly quick to take hold of abstract ideas, but the self-marker theory of immunity was--like everything else in immunology--almost impossible to explain to laymen, no matter how intelligent. "This process," Hamelin said hesitantly. "It takes a long time?" "About six hours per subject, and we can handle only one man at a time. That means that we can count on putting no more than seven thousand troops into the field by the turn of the century. Every one will have to be a highly trained specialist, if we're to bring the war to a quick conclusion." "Which means no civilians," Hamelin said. "I see. I'm not entirely convinced, but--by all means let's see how it's done." * * * * * Once inside, the under-secretary tried his best to look everywhere at once. The room cut into the rock was roughly two hundred feet high. Most of it was occupied by the bulk of the Re-Education Monitor, a mechanism as tall as a fifteen-storey building, and about a city block square. Guards watched it on all sides, and the face of the machine swarmed with technicians.