Sallie sat up in her disordered cot with a start of alarm when Ambrizette came in to wake her, as she had directed before she lay down. She had scarcely slept at all amid dreadful dreams, and was still very weary, both body and mind. She had not yet had time to forget the horrors of over-night.

But she had no desire to dwell on them, and—there was the day\'s work awaiting her. Twenty minutes later she was on her way to the bridge, to relieve Da Costa.

That was not the first occasion, by many, on which she had had to fill a man\'s place. For Captain Dove had trained her to all the responsibilities of the sea. Da Costa touched his cap obsequiously to her and gave her the course, which she repeated after him, with mechanical precision.

As he turned to go, yawning wearily, "If you\'ll send and have me woke out again whenever you feel like it, Miss Sallie," he said with an ingratiating flourish, "I\'ll—"

"But Mr. Yoxall will be taking the next watch, won\'t he?" she asked, renewed doubt and distrust in her tired eyes.

The promoted Portuguese quartermaster shrugged his shoulders and spread out his hands.

"You and I must stand watch and watch for a little, Miss Sallie," he told her with a self-satisfied smirk. "The chief mate is sick—of a fever. That Hobson he is already dead and over the side. And Captain Dove has sent order that he is not to be disturbed—unless necessary. He is broke down, he says, with illness and worry."

"Wait a minute, then, Mr. Da Costa," she said, so imperatively that he halted and let her pass. "I won\'t be long, and then I\'ll stay on duty till evening."

She hurried below by the stairway behind the chart-house, and went straight along the alleyway to Reuben Yoxall\'s room. She was very much alarmed; she knew how sudden and deadly the dreaded West African fever could be. She did not doubt that the wretched Hobson had fallen a victim to it.

All was quiet within the chief mate\'s room. She knocked gently, and the door was opened almost at once. A young man in an ill-fitting, coal-blackened suit of blue dungaree looked inquiringly out at her and then frowned.

"Keep to the other side of the passage, please," he requested crisply. "This room\'s in strict quarantine, and the risk of infection—"

"Oh, never mind about that," she broke in. "It\'s no worse for me than for you. And I must speak to Rube—Mr. Yoxall. Is he very bad? How did you—"

She had recognised him by his voice. Without his horrible mask he looked so much younger than she had supposed him that she had at first wondered who he could be, although his keen, resolute face was haggard and lined, his pale lips dreadfully drawn at the corners, and hideous remembrances still seemed to lurk behind his steady grey eyes.

"He\'s asleep at present—and pretty bad," said the stranger sorrowfully. "I had to give him an opiate. I volunteered to look after him—which was the very least I could do. There was no one else who knew anything, and, although I\'m not a doctor, I know some of the tricks of the trade.

"And I know enough," he added, "to warn you that you must please stay away from here in the meantime."

"I won\'t," said Sallie simply. "He\'s my best friend, Mr.—"

"Carthew\'s my name," the young man in the doorway informed her.

"He\'s my best friend, Mr. Carthew. And—you must let me help."

Mr. Carthew considered the matter, and nodded.

"All right," he agreed. "If you like to see to his food—what the ship\'s cook has left at the door will do him no good." And she listened attentively while he went on to tell her what would be best for the sick man.

"Ambrizette will prepare it and bring it along," she promised. "And—you\'ll let me see him next time I come down?"

"As soon as he\'s fit to see anyone," her new acquaintance assured her. And with that Sallie was quite content. She felt intuitively that she could trust him.

"Are you—all right, yourself?" she asked.

"Perfectly all right," he assured her. "And very glad of the chance to repay some small part of what I owe—our friend."

"No one else will come near you here," she said reflectively. "It may all be for the best in the end."

He nodded again, and, as she turned away, shut the door very quietly.

She hurried aft, to instruct Ambrizette as to the food to be prepared and carried to the sick man\'s door, and no less hastily returned to the bridge. Da Costa left it by the other ladder; he evidently did not care to come too near her then. And there she remained all day, with only the sullen, silent man at the wheel for company.

Once during the afternoon she slipped down to ask how the mate was, and found him delirious. Slyne came on deck as she returned to her post, and frowned angrily as she told him, in answer to his quick question, where she had been. He had obviously intended to join her up there, but thought better of that.

"You mustn\'t go near him again, Sallie," he called to her peremptorily. "Captain Dove will be very ill-pleased."

"I can\'t help that," she answered, thankful so to escape Jasper Slyne\'s company. And he turned away with a still blacker frown. It was tiresome talking against the stiff head-wind.

The day dragged out its dreary length, until, late in the evening, Da Costa came on deck again.

"I\'m good for all night now," he told Sallie from a safe distance. "Captain Dove\'s still sound asleep, although the mate\'s been making no end of a row."

"I\'ll be up again some time in the morning watch, then," she told him, and was soon knocking at the door of Yoxall\'s room.

Carthew\'s face was very grave when he looked out.

"Is he worse?" she asked breathlessly.

"Better—in one way," the young American answered. "He\'s conscious now. He\'s had some of the soup you sent along."

"Can I see him?" she begged.

"He\'s just been speaking of you. He told me to ask you not to come near him again."

She choked back a dry sob, and had pushed past him into the room before he could interfere.

"I\'ll sit with him for an hour or two now, while you get a sleep," she said, and stifled another sob as she saw how the sick man\'s sunken eyes grew glad at sight of her.

Nor did anything that the acting doctor could urge make any difference in her determination; and she hushed the mate\'s whispered protests with a brave smile.

"We\'re going to pull you through, Rube, between us," she whispered back, bending over him. "And you\'re going to obey orders for the present, instead of giving them. So don\'t say any more about it now."

She had seated herself on a camp-stool beside him. Carthew, convinced that it would be futile to argue any further with her, was evidently only too glad to stretch himself on the sofa and draw the curtains. And almost at once he fell fast asleep.

It was very nearly midnight before he moved and woke and sprang to his feet. And Sallie was still sitting there with one of the mate\'s huge hands between both of hers.

"He looks a little better, don\'t you think?" she asked wistfully before she tiptoed out of the room. And Carthew, after a prolonged glance at his patient, nodded approval and hope.

That night and the next day and the next again passed without any change of conditions on board. Captain Dove was still confined to his room, and would not even see Slyne, who had, therefore, to live alone, bored to the last limit, not so much afraid of the fever as shirking any needless risk of infection, his intercourse with Sallie confined to an occasional shouted caution or inquiry.

Da Costa took the bridge by night and she by day. And every night she relieved Carthew for a few hours from his unremitting attendance on the sick man. She was with Reuben Yoxall when he died.

What passed between the two of them during that last vigil is not to be told. But the dead man\'s face was very calm and content when Sallie at length roused Carthew from his scanty rest to tell him that the appointed end had come.

"But you promised to call me up," he said, most unhappy for her.

"If there was any need," she corrected him gently. "But there was none. He knew—before I came in."

Her downcast eyes were dry, but grie............