Calder turned the letter over and over, as though he could not make up his mind what in the world to do with it.
"Can a sunstroke destroy the optic nerve?" he asked at length.
"A mere sunstroke? No," replied the doctor. "But it may be the occasion. For the cause one must look deeper."
Calder came to a stop, and there was a look of horror in his eyes. "You mean—one must look to the brain?"
"Yes."
They walked on for a few paces. A further question was in Calder's mind, but he had some difficulty in speaking it, and when he had spoken he waited for the answer in suspense.
"Then this calamity is not all. There will be more to follow—death or—" but that other alternative he could not bring himself to utter. Here, however, the doctor was able to reassure him.
"No. That does not follow."
Calder went back to the mess-room and called for a brandy-and-soda. He was more disturbed by the blow which had fallen upon Durrance than he would have cared to own; and he put the letter upon the table and thought of the message of renunciation which it contained, and he could hardly restrain his fingers from tearing it across. It must be sent, he knew; its destruction would be of no more than a temporary avail. Yet he could hardly bring himself to post it. With the passage of every minute he realised more clearly what blindness meant to Durrance. A man not very clever, as he himself was ever the first to acknowledge, and always the inheritor of the other places,—how much more it meant to him than to the ordinary run of men! Would the girl, he wondered, understand as clearly? It was very silent that morning on the verandah at Wadi Halfa; the sunlight blazed upon desert and river; not a breath of wind stirred the foliage of any bush. Calder drank his brandy-and-soda, and slowly that question forced itself more and more into the front of his mind. Would the woman over in Ireland understand? He rose from his chair as he heard Colonel Dawson's voice in the mess-room, and taking up his letter, walked away to the post-office. Durrance's letter was despatched, but somewhere in the Mediterranean it crossed a letter from Ethne, which Durrance received a fortnight later at Cairo. It was read out to him by Calder, who had obtained leave to come down from Wadi Halfa with his friend. Ethne wrote that she had, during the last months, considered all that he had said when at Glenalla and in London; she had read, too, his letters and understood that in his thoughts of her there had been no change, and that there would be none; she therefore went back upon her old argument that she would, by marriage, be doing him an injury, and she would marry him upon his return to England.
"That's rough luck, isn't it?" said Durrance, when Calder had read the letter through. "For here's the one thing I have always wished for, and it comes when I can no longer take it."