There was orderly behavior, there was chaotic behavior; and on their border, in their interplay, so to speak, lay a very large and convoluted zone, the realm of the complex. This was the zone in which viriditas made its appearance, the place where life could exist. Keeping life in the middle of the zone of complexity was, in the most general philosophical sense, what the longevity treatments had been about— keeping various incursions of chaos (like arrhythmia) or of order (like malignant cell growth) from fatally disrupting the organism.

But now something was causing the gerontologically treated individual to go from negligible senescence to extremely rapid senescence— or, even more disturbingly, straight from health to death, without senescence at all. Some heretofore unseen irruption of chaos or order, into the border zone of the complex. This was how it seemed to him, in any case, at the end of one very long session of reading the most general descriptions of the phenomenon he could find. And it suggested certain avenues of investigation as well, in the mathematical descriptions of the complexity-chaotic border, likewise the order-complexity border. But he lost this holistic vision of the problem in one of his blankouts, the train of thought concerning the substance of the math gone forever. And it had probably (he tried to console himself afterward) been too philosophical a vision to do him any good anyway. The explanation after all was not going to be obvious, or else the massive concerted effort of medical science would have searched it out by now. On the contrary; it was likely to be something very subtle in the biochemistry of the brain, an arena that had resisted five hundred years of effort to investigate it scientifically, resisted like the hydra, every new discovery only suggesting another headful of mysteries. . . .