Salted with Fire by George MacDonald — Read

The next day, Isy, although very weak, was greatly better. She was, however, too ill to get up; and Marion seemed now in her element, with two invalids, both dear to her, to look after. She hardly knew for which to be more grateful-her son, given helpless into her hands, unable to repel the love she lavished upon him; or the girl whom God had taken from the very throat of the swallowing grave. But her heart, at first bubbling over with gladness, soon grew calmer, when she came to perceive how very ill James was. And before long she began to fear she must part with her child, whose lack of love hitherto made the threatened separation the more frightful to her. She turned even from the thought of Isy's restoration, as if that were itself an added wrong. From the occasional involuntary association of the two in her thought, she would turn away with a sort of meek loathing. To hold her James for one moment in the same thought with any girl less spotless than he, was to disgrace herself!

James was indeed not only very ill, but growing slowly worse; for he lay struggling at last in the Backbite of Conscience, who had him in her unrelaxing jaws, and was worrying him well. Whence the holy dog came we know, but how he got a hold of him to begin his saving torment, who shall understand but the maker of men and of their secret, inexorable friend! Every beginning is infinitesimal, and wrapt in the mystery of creation.