The Silver Plague

Like a tide, the horror of the silver death was sweeping to inundate the inhabited worlds—with only Varon to halt its flood—and he was already marked by the plague he fought.
Fermin, the Arch-Mutant , had risen before dawn and in the garnet-colored light that passed for morning on Ganymede, repaired to the magnificent austerity of his cloister where he received an endless series of reports.
He had been reading Seville-Lorca the previous evening, delighting in the incredible pages which had been the great historians' dying contribution to their worlds, and to which he had every intention of adding an ironic anti-climax of his own. He sat in an austere Jadite chair basking in the archaic warmth of an open hearth, and watched whimsically for a moment how the darting flames reflected a bright patina on the fur of the somnolent Felirene at his feet. There was a chapter on the Jovian Societies he wanted to re-read. Not for the brilliant, facile style in which Seville-Lorca presented the distilled chronicles of the Jovian Moons, but for that deeper purport which is the notation of the heart.
Slowly, Fermin became absorbed in the photo-plastic record on the stand before him, unrolling in synchronized timing with his own reading speed.
... It seems natural, I suppose, human nature being as it is—that the Mother Planet should maintain an attitude of supercilious aloofness. But then, it is axiomatic we can never quite love those we have wronged. And the history of the colonization of the major Jovian Moons is anything but exalting.
When at the close of the 'Great Unrest,' as the twenty-third century is popularly known, it was definitely established that the ratio of Mutants to the grand total of normal populations was becoming an increasingly dangerous potential, they were given their choice of a charter to the newly explored Jovian Moons—a magnanimous gesture which ignored with olympic indifference the fact that at least one—Ganymede—had already a civilization of its own.