"That is so," agreed the professor glumly, "and what is worse, they must have recognized us."

The professor, as we have hinted before, had been with the boys on that memorable cruise to tropic waters, when Dampier and Walstein very nearly succeeded in marooning the Dacre party and stealing their treasure recovered from a sunken galleon. He, as well as the boys, knew the desperate character of the two men.

"All we can do is to keep as nearly as possible in this spot all night," advised Jack; "then, as soon as daylight comes, the storm may abate, and we can take some action."

And so it was arranged. Leaving the wheel to Sandy, who was a muscular youth, Jack dived below to attend to the engines, which he had neglected for some time. Luckily, however, the machinery was working smoothly. The professor remained with Sandy on the bridge, doing what he could to help in controlling the vessel through the fury of the night.

Somehow the long hours of darkness passed away, and daylight came. The sunrise was yellow and sickly, breaking through ragged clouds. A chilly wind swept across the lake, but the backbone of the storm was broken.

But, as Jack had feared deep down in his heart, on all the expanse of leaden, rolling water, there was no sign of another craft. The Sea Ranger was alone in the desolate scene. A hasty examination had shown that she had suffered no material damage in the collision. Some paint was scraped off, but that was all.

Sandy got breakfast, which they ate with faint hearts. Jack, for his part, could hardly swallow more than a few mouthfuls of bacon and bread and gulp down a cup of coffee. His mind was actively busied with plans to rescue his brother from the hands of men he knew to be unscrupulous, clever and revengeful.

"It's hardly likely that they'll neglect such a chance to get even on us for sending them to jail and recovering the treasure," thought Jack, with a sigh that was almost a groan.

After a hasty meal, he announced his plans. A consultation of the chart had shown them to be about opposite—so far as Jack could judge—a place called Rockport. The others heartily agreed with his determination, which was to head in to that place, and, by the use of the telegraph and the assistance of the police of the town, to get on the track of the mysterious tug which had vanished with Tom.

While the Sea Ranger is cutting through the seas toward her hastily determined destination, let us see what had become of Tom on board the tug that carried no lights.