venturing near and might hear their voices.
From a distant side of the island they suddenly heard more shots. They broke out in a perfect fusillade of gunfire, and the rocks flung back the echoes, mingled with yells of rage. At the same time, they again heard the sound of the Sleuth's engine, slower this time, as though the craft were but crawling along.
"I can't understand this," said Chet. "We heard them leave the cove a little while ago. Now they're away down the shore and going slow."
"Perhaps they're having engine trouble," said Biff mournfully.
"I can't figure it out at all. It's tough to be sitting here in the dark, not knowing whether they've got away or not."
"I don't dare let myself think they haven't got away," declared Biff, with determination.
An hour passed. The sounds of the motorboat had long since died away. Once in a while the chums heard voices back in the grove and they knew that at least some of the gangsters had been left on the island. Whether the others had left in pursuit of the Hardy boys, they could not tell. Had they known of the Hardys' coup in taking the gangsters' two boats they would have felt more relieved in mind. The chill of approaching morning had settled over the island, and they huddled to-
