The moon was well up when the small boat in which our young detective was seated with Mr. Grey appeared in the bay approaching the so-called manufactory of Wellgood. The looked-for light on the waterside was not there. All was dark except where the windows reflected the light of the moon.

This was a decided disappointment to Sweetwater, if not to Mr. Grey. He had expected to detect signs of life in this quarter, and this additional proof of Wellgood’s absence from home made it look as if they had come out on a fool’s errand and might much better have stuck to the road.

“No promise there,” came in a mutter from his lips. “Shall I row in, sir, and try to make a landing?”

“You may row nearer. I should like a closer view. I don’t think we shall attract any attention. There are more boats than ours on the water.”

Sweetwater was startled. Looking round, he saw a launch, or some such small steamer, riding at anchor not far from the mouth of the bay. But that was not all. Between it and them was a rowboat like their own, resting quietly in the wake of the moon.

“I don’t like so much company,” he muttered. “Something’s brewing; something in which we may not want to take a part.”

“Very likely,” answered Mr. Grey grimly. “But we must not be deterred—not till I have seen—” the rest Sweetwater did not hear. Mr. Grey seemed to remember himself. “Row nearer,” he now bade. “Get under the shadow of the rocks if you can. If the boat is for him, he will show himself. Yet I hardly see how he can board from that bank.”

It did not look feasible. Nevertheless, they waited and watched with much patience for several long minutes. The boat behind them did not advance, nor was any movement discernible in the direction of the manufactory. Another short period, then suddenly a light flashed from a window high up in the central gable, sparkled for an instant and was gone. Sweetwater took it for a signal and, with a slight motion of the wrist, began to work his way in toward shore till they lay almost at the edge of the piles.

“Hark!”

It was Sweetwater who spoke.

Both listened, Mr. Grey with his head turned toward the launch and Sweetwater with his eye on the cavernous space, sharply outlined by the piles, which the falling tide now disclosed under each contiguous building. Goods had been directly shipped from these stores in the old days. This he had learned in the village. How shipped he had not been able to understand from his previous survey of the building. But he thought he could see now. At low tide, or better, at half-tide, access could be got to the floor of the extension and, if this floor held a trap, the mystery would be explainable. So would be the hovering boat—the signal-light and—yes! this sound overheard of steps on a rattling planking.

“I hear nothing,” whispered Mr. Grey from the other end. “The boat is still there, but not a man has dipped an oar.”

“They will soon,” returned Sweetwater as a smothered sound of clanking iron reached his ears from the hollow spaces before him. “Duck your head, sir; I’m going to row in under this portion of the house.”

Mr. Grey would have protested and with very good reason. There was scarcely a space of three feet between them and the boards overhead. But Sweetwater had so immediately suited action to word that he had no choice.

They were now in utter darkness, and Mr. Grey’s thoughts must have been peculiar as he crouched over the stern, hardly knowing what to expect or whether this sudden launch into darkness was for the purpose of flight or pursuit. But enlightenment came soon. The sound of a man’s tread in the building above was every moment becoming more perceptible, and while wondering, possibly, at his position, Mr. Grey naturally turned his head as nearly as he could in the direction of these sounds, and was staring with blank eyes into the darkness, when Sweetwater, leaning toward him, whispered:

“Look up! There’s a trap. In a minute he’ll open it. Mark him, but don’t breathe a word, and I’ll get you out of this all right.”

Mr. Grey attempted some answer, but it was lost in the prolonged creak of slowly-moving hinges somewhere over their heads. Spaces, which had looked dark, suddenly looked darker; hearing was satisfied, but not the eye. A man’s breath panting with exertion testified to a near-by presence; but that man was working without a light in a room with shuttered windows, and Mr. Grey probably felt that he knew very little more than before, when suddenly, most unexpectedly, to him at least, a face started out of that overhead darkness; a face so white, with every feature made so startlingly distinct by the strong light Sweetwater had thrown upon it, that it seemed the only thing in the world to the two men beneath. In another moment it had vanished, or rather the light which had revealed it.

“What’s that? Are you there?” came down from above in hoarse and none too encouraging tones.

There was none to answer; Sweetwater, with a quick pull on the oars, had already shot the boat out of its dangerous harbor.