A similar state of weakness, perturbed by the excitement of his passion for Constance Temple, might surely also have conjured up the vision which he thought he saw the night of our leaving Oxford in the summer.
These thoughts, my dear Edward, gave me great relief; for it seemed a comparatively trivial matter that my brother should be ill, even seriously ill, if only his physical indisposition could explain away the supernatural dread which had haunted us for the past six months.

The clouds were breaking up.

It was evident that John had been seriously unwell for some months; his physical weakness had acted on his brain; and I had lent colour to his wandering fancies by being alarmed by them, instead of rejecting them at once or gently laughing them away as I should have done.

But these glad thoughts took me too far, and I was suddenly brought up by a reflection that did not admit of so simple an explanation.

If the man's form my brother saw at Oxford were merely an effort of disordered imagination, how was it that he had been able to describe it exactly like that represented in this picture?
He had never in his life been to Royston, therefore he could have no image of the picture impressed unconsciously on or hidden away in his mind.