"Good-bye!" shouted Tremayne in reply, as the torpedo-boat swung round and headed back to the battleship, and he gave the order to go ahead again at full-speed. In another hour they were off the Land's End, and from there they headed out due south-west into the Atlantic. They had hardly made another hundred miles before it began to grow light, and then it became necessary to keep a bright look-out for the air-ship, for according to what they had heard from the commander of the torpedo-boat she might be sighted at any moment as soon as it was light enough to see her. Another hour passed, but there was still no sign of the air-ship. This of course was to be expected, for they had still another seventy-five miles or so to go before the rendezvous was reached. "Steamer to the south'ard!" sang out the man on the forecastle, just as Tremayne came on deck after an attempt at a brief nap. He picked up his glass, and took a good look at the thin cloud of smoke away on the southern horizon. From what he could see it was a large steamer, and was coming up very fast, almost at right angles to the course of the _Lurline_. Fifteen minutes later he was able to see that the stranger was a warship, and that she was heading for Queenstown. She was therefore either a British ship attached to the Irish Squadron, or else she was an enemy with designs on the liners bound for Liverpool. In either case it was most undesirable that the yacht should be overhauled again. Any mishap to her, even a lengthy delay, might have the most serious consequences. A single unlucky shell exploding in her engine-room would disable her, and perhaps change the future history of the world. Tremayne therefore altered her course a little more to the northward, thus increasing the distance between her and the stranger, and at the same time ordered the engineer to keep up the utmost head of steam, and get the last possible yard out of her. The alteration in her course appeared to be instantly detected by the warship, for she at once swerved off more to the westward, and brought herself dead astern of the _Lurline_. She was now near enough for Tremayne to see that she was a large cruiser, and attended by a brace of torpedo-boats, which were running along one under each of her quarters, like a couple of dogs following a hunter. There was now no doubt but that, whatever her nationality, she was bent on overhauling the yacht, if possible, and the dense volumes of smoke that were pouring out of her funnels told Tremayne that she was stoking up vigorously for the chase. By this time she was about seven miles away, and the _Lurline_, her twin screws beating the water at their utmost speed, and every plate in her trembling under the vibration of her engines, rushed through the water faster than she had ever done since the day she was launched. As far as could be seen, she was holding her own well in what had now become a dead-on stern chase.