Frank was very cautious as he eased the rope out around a cleat, after which, when the spinnaker boom had drawn forward, he found that he could luff the boat. When she had swerved from her course a trifle he could see the other boat close ahead, and it gave him some idea how fast both craft were traveling. She seemed nothing but sail. Indeed, except for the torn-up track of foam that marked her passage, she looked much less like a boat than some wonderful phantom thing flying at an astonishing speed across the sea. Swiftly as she sped, however, there was no doubt that the sloop was creeping up on her, and Frank felt himself quivering all through as the distance between them lessened yard by yard. Then suddenly the contour of her canvas changed and she swung around from leeward across the sloop's bows. Frank's heart gave a sudden leap as he wondered what he must do and his nerve almost deserted him, until Harry called again. "More guy!" he sang out. "They're trying to luff us. We must keep their weather." Although fearful that it might overpower him, Frank slacked the guy out inch by inch, and as the sloop came up a little farther he saw the whole of the other boat again. The sloop's bowsprit was level with her quarter. She was scarcely a dozen yards away, leaping, plunging, swaying through a flung-up mass of foam, but they were steadily drawing up with her, and the boy could have shouted in the fierce excitement of the moment. Two or three minutes later they were clear ahead. He could no longer see the other boat, and he dared not risk a glance back at her. Indeed, it was a relief to him when Harry came scrambling aft. "We'll get that guy in again," he said. "Unless something gives out, those folks won't catch us up." They had a desperate struggle with the guy, but Harry laughed gayly when they had made it fast. "They'll follow us on to Bannington's, sure," he said. "We should be there in half an hour, and I don't mind allowing that I'll be glad to get some of this sail off her." After a while a black bank of cloud spread across the moon, and Frank wondered anxiously how much of the half hour had gone. He had now only the pull on the tiller to guide him as they drove on furiously, and the strain of concentrating all his faculties on his task was beginning to tell on his strength. Once or twice he imagined that he came perilously near to bringing the mainboom over, and he would have called Harry to the helm if he had felt certain that he could cling to the slender lurching spar as well as his comrade could. He was getting nervous, and the seething rush of water past the boat was becoming bewildering.