He had just come into one of the wards where he belonged, and was about to begin his rounds, when his eye fell upon a couple of nuns, who were in the habit of coming every day to assist and relieve some of the nurses. They belonged to the order of Gray Nuns, and were clad in the loose and homely garb worn by that sisterhood. But little could be seen of their faces, for they wore the close, gray bonnet, with a wide frill of black tissue plaited about the edge of a little black silk cap worn underneath, and white bandages about their foreheads and chins. The only way that they could be distinguished from each other—for they were of the same height—was by a pair of double blue glasses which one of them wore. But they were very helpful, very sweet and gentle in their ways, particularly the sister in blue glasses, who was known as Sister Angela, or “The Angel in Gray,” as the poor soldiers and patients soon learned to call her. CHAPTER XXI. DR. WINTHROP PASSES THROUGH DEEP WATERS. “Perhaps they will know of some one whom I can get to nurse Tillinghast,” Dr. Winthrop muttered, as he watched these two Sisters of Mercy flitting from couch to couch, intent only upon relieving the suffering around them. He had never yet spoken with them, for on his approach they would always modestly withdraw, and stand with bowed heads and crossed hands until he had made his explanation, given his orders to the head nurse, and passed on. Now, however, he walked directly toward one of them, who was bathing the hot face and hands of a poor fellow who had lost a leg during the insurrection. Her back was toward him and he did not know which one she was until he stepped beside her and she turned her face to him; then he caught sight of the blue glasses and he saw it was Sister Angela. “Can I speak with you a moment, Sister?” he inquired in a low tone. She stepped back, crossed her hands upon her bosom, bowed her head and waited to hear what he had to say. “My friend has been suddenly stricken down,” he began, “I must have a competent nurse at once, or he will die. Do you know of such a one?” “No, monsieur,” she replied, “every nurse in Paris is engaged—see!”—with a sweeping gesture of the hand, though she did not raise her head or her glance—“you have not sufficient help even here, and hundreds are dying outside for the want of proper care.” “Then, what shall I do?” cried Dr. Winthrop, and there was a note of agony in his tone. His friend had not spared himself for others, and he could not bear that he should die from lack of care. “Has monsieur no friends who could come to him?” inquired the nun. “No; none who would be of any service at such a time,” and he shivered as he thought of bringing any member of his family into that pest-house. Norman was the only one who occurred to him, and he was needed too much elsewhere to be thought of for a moment. “Monsieur is very ill?” said the nun inquiringly.