But he had nothing to clutch at, and could only go. Turning almost a complete somersault, he went off the roof and down into the water with a loud splash. “A good thing he didn’t strike the deck on his head. That would have settled him. Even in the water he may not be altogether safe.” This last thought made Nick let himself down quickly from the block and sent him scurrying to the stern of the yacht, where he could get to his skiff. It was not an easy task to get down without being seen, for the noise of the scuffle had attracted three men who slept forward, and were part of the deck crew of the vessel. But Nick reached his skiff, and, as he heard a gasping cry for help some distance out in the river, he rowed rapidly in that direction. He was only just in time. In the faint moonlight he made out a ghastly white face--it was Prince Marcos’. Nick saw that he was swimming on his back almost unconsciously. There is little doubt but that, if Marcos had not been a magnificent swimmer, he would have drowned before the detective reached him. As it was, his arms and legs moved practically of their own volition. They had been used so often in swimming that they went through the motions mechanically so long as he had strength enough to use them at all. As Nick Carter reached for him, the nearly unconscious man grabbed at the boat, while the water gurgled in his throat and seemed to be choking him. It was an unfortunate grab. The skiff tipped over, and before the detective could save himself, he was in the water with the man he had come to rescue. Now began one of those awful struggles that good swimmers dread so much, and yet which may come to any of them at any time. Nick Carter knew it would be useless to expostulate with the drowning man. He must try to beat him off. It would be the only way to save both their lives. But Marcos was strong, and in the water he could use his strength to the disadvantage of his would-be rescuer, even though Nick was much the more powerful of the two. At the first collision, they went down together. Here was Nick Carter’s chance. The detective had often practiced holding his breath for long periods, so the ducking was not so trying to him as it was to Marcos. For this reason Nick deliberately stayed below the surface as long as he could, with the object of taking all the life out of the other man. It would be possible to handle him if he were unconscious. But Marcos had good lungs, and though they were under the water long enough to have rendered many a person unconscious, they came up without any material change in the condition of either. Marcos had recovered somewhat from the blow of the chair, which had been the main cause of his dazed condition. The water had revived him to some extent, but he hardly knew what he was doing. He fought wildly with Nick, trying to hold to him, and down they went again.