The Lost Stradivarius by John Meade Falkner

A month later Mrs. Temple wrote to John warning him of the state in which Constance now found herself, and begging him to return at least for a few weeks in order that he might be present at the time of her confinement. Though it would have been in the last degree unkind, or even inhuman, that a request of this sort should have been refused, yet I will confess to you that my brother's recent strangeness had prepared me for behaviour on his part however wild; and it was with a feeling of extreme relief that I heard from Mrs. Temple a little later that she had received a short note from John to say that he was already on his return journey. I believe Mrs. Temple herself felt as I did in the matter, though she said nothing.

When he returned we were all at Royston, whither Mrs. Temple had taken Constance to be under Dr. Dobie's care. We found John's physical appearance changed for the worse. His pallor was as remarkable as before, but he was visibly thinner; and his strange mental abstraction and moodiness seemed little if any abated. At first, indeed, he greeted Constance kindly or even affectionately. She had been in a terrible state of anxiety as to the attitude he would assume towards her, and this mental strain affected prejudicially her very delicate bodily condition. His kindness, of an ordinary enough nature indeed, seemed to her yearning heart a miracle of condescending love, and she was transported with the idea that his affection to her, once so sincere, was indeed returning. But I grieve to say that his manner thawed only for a very short time, and ere long he relapsed into an attitude of complete indifference. It was as if his real, true, honest, and loving character had made one more vigorous effort to assert itself -- as though it had for a moment broken through the hard and selfish crust that was forming around him; but the blighting influence which was at work proved seemingly too strong for him to struggle against, and riveted its chains again upon him with a weight heavier than before. That there was some malefic influence, mental or physical, thus working on him, no one who had known him before could for a moment doubt. But while Mrs. Temple and I readily admitted this much, we were entirely unable even to form a conjecture as to its nature. It is true that Mrs. Temple's fancy suggested that Constance had some rival in his affections; but we rejected such a theory almost before it was proposed, feeling that it was inherently improbable, and that, had it been true, we could not have remained entirely unaware of the circumstances which had conduced to such a state of things. It was this inexplicable nature of my brother's affliction that added immeasurably to our grief. If we could only have ascertained its cause we might have combated it; but as it was, we were fighting in the dark, as against some enemy who was assaulting us from an obscurity so thick that we could not see his form. Of any mental trouble we thus knew nothing, nor could we say that my brother was suffering from any definite physical ailment, except that he was certainly growing thinner.