They passed the last jutting point of the sinister island and the bow of the Sleuth was headed toward the coast.
“Perhaps we won’t have to go all the way to Rock Harbor,” suggested Joe. “If we could meet a ship we might get help.”
“It seems to me I see a light now. Running low on the water. Do you see it?”
Joe peered into the darkness.
“I believe you’re right,” he said finally. “It seems to be coming this way, too.”
“Perhaps some more of the gang.”
“I hadn’t thought of that. Better not go too close.”
Frank eyed the approaching light warily. It was just a faint gleam in the darkness and he judged it was from a motorboat which was most certainly bound toward Blacksnake Island. Eventually he could hear the steady throb of the engine.
After a moment or so he started up excitedly.
“Joe! I’d know that engine anywhere.”
“So would I! It’s—”
“The Napoli!”
He spun the wheel about so that the Sleuth would cut across the bows of the approaching craft. Steadily, through the darkness, came the throbbing of the engine, and as the boat came closer the Hardy boys became more and more convinced that it was Tony Prito’s craft.
“I’ve been wondering what became of him,” Frank declared. “When he didn’t show up earlier I began to think he must have had to call off the trip.”
“It may not be him after all, but I’m sure it’s his boat. If it isn’t I’ll never believe my ears again.”
The two boats approached one another. Frank shut down the engine of the Sleuth, rose from his seat, and shouted:
“Napoli, ahoy!”
Almost immediately the roar of the other engine died to a murmur and a well-known voice replied:
“This is the Napoli. Who are you?”
It was the voice of Tony Prito. Joe gave a yell of delight.
“It’s us!” shouted Frank. “The Hardy boys!”
They could hear sounds of excited talking in the other boat, and a suppressed cheer.
“Coming over!” Tony called out, and in a few minutes the two boats had drawn up alongside. In the glare of the headlight Frank and Joe could see Tony Prito, Jerry Gilroy and Phil Cohen.
Their greetings were cut short when the boys saw the two trailing boats and Frank tersely explained the situation.
“You couldn’t have come at a better time. We found Chet and Biff on the island. They’re still there. We tried to escape, but got separated and only Joe and I got away. Chet and Biff are in hiding somewhere and we stole the other motorboats.”
“Whose motorboats?” asked Jerry.
“Chet and Biff were captured by a gang of crooks who mistook them for us. These fellows had a cave on the island and two motorboats of their own. When we made our getaway we towed their boats away with us so the men are all marooned there.”
A chorus of excited questions broke forth as the newcomers demanded further details, but Frank went on:
“We’re going to the mainland for help. What we want you to do is take charge of these two motorboats and keep cruising around the island to see that the gang doesn’t get away.”
“Good!” approved Phil. “And if we can pick up Chet and Biff we’ll do it.”
“If you can, without letting the gang get hold of those boats again.”
“Fine!” Tony declared. “We’ll take the boats. Throw over that rope.”
He caught the rope deftly, and the captured motorboats were soon being towed by the Napoli, leaving the Hardy boys’ craft free for its flight to the mainland.
“We’ll be back as soon as we can,” called out Frank.
“We’ll be watching for you.”
“Good. No use wasting any more time. Good luck!”
“Good luck!” shouted the others.
Frank bent over the wheel again. The engine of the Sleuth roared as the speedy craft turned toward the mainland. The Napoli, in its turn, began to forge ahead toward Blacksnake Island, its speed somewhat lessened now by the drag of the captured boats. Tony, Jerry and Phil were agog with excitement over this strange encounter in the darkness and the sensational news the Hardy boys had given them.
So the two motorboats went their separate ways in the darkness of the night—one to the mainland, the other toward the sinister island where Chet Morton and Biff Hooper were marooned with the gangsters.
XXI
At the Island
In the meantime, what of Chet Morton and Biff Hooper?
When they took the wrong turn in the trail it was some time before they realized that the Hardy boys were not running along before them. They were blundering along through the undergrowth, in complete darkness, trusting to their chums to guide them through, when finally Chet stopped, panting.
“Frank and Joe must be running like deer,” he muttered. “I can’t hear them at all.”
“We were all mighty close together a little while ago,” returned Biff.
“I know. And they seem to have disappeared all of a sudden.” The thought struck Chet that they might be on the wrong trail. “Do you think we could have taken a wrong turn?”
Biff listened. “There’s no one ahead of us, that’s sure,” he said at last. “We must have got separated.”
As this conviction forced itself upon them, the two lads were overwhelmed with disappointment. They knew that the Hardy boys would have little enough time to gain the boat and escape without waiting for them, and at the thought that they might be again left on the island at the mercy of their captors they were profoundly discouraged.
“We’re up against it again, I guess,” declared Chet. “Well, I think we’d better follow this trail anyway, wherever it leads to. Remember what Frank said—that if even one of us reached the boat safely he could get to the mainland
