Danny and the girls moved away from Crocodile Island. All of them watched anxiously to see if they were being followed.
Other tourists were leaving in their motorboats. Nancy wondered if one of them might contain a spy from the Ecology Company, sent out to pursue the Pirate.
“I hope not,” the girl detective thought.
Nancy observed through binoculars what directions the various craft took. One seemed to stalk the Pirate, and Nancy had an uneasy feeling about it.
“Do you see anything?” Bess wanted to know.
“There’s a fast motorboat called The Whisper,” Nancy replied. “It seems to be tailing us.”
“Is that unusual?” George asked. “After all, other people might be heading for Key Biscayne.”
“Of course,” Nancy answered. “It’s just that most of the boats have scattered. This one stays right in the wake of our boat.”
“Oh, oh,” Danny murmured. “Maybe they want to find out where we’re headed. On the other hand, they wouldn’t really have to bother. Anyone can check the boat registry to see who owns the Pirate and where we live.”
“That’s great,” George said. “They already know who we are, and now they can find out where we’re staying!”
Bess became alarmed. “Let’s head for home!” she begged.
Danny looked at Nancy. “What do you say?”
“I’m not ready to leave Crocodile Island just yet. Let’s go around it and see what’s on the other side. We might pick up a clue.”
Danny nodded. “Sure. We may even find out if a loose crocodile caused the alarm.”
“What else would?” George asked.
“You girls. Someone might have recognized not Anne, Elizabeth, and Jackie, but Nancy, Bess, and George, and wanted you off the premises.”
Nancy agreed that it was a possibility. “We’re getting to be notorious.” She chuckled.
Danny followed the shoreline of the key. The Whisper stayed right behind them, and soon there was no doubt in the girls’ minds that the boat was pursuing them. The fast craft finally pulled alongside the Pirate.
With some apprehension the young people watched the two men on The Whisper’s deck. Both had swarthy complexions and unpleasant faces. One of them shouted, “Get away from this island!”
“Why?” Danny asked innocently.
“Because it’s private property!”
“The water isn’t!” George pointed out “Besides, we’re not doing any harm!”
“We don’t want you here,” the man insisted and shook his fist. “Now get lost!”
“Who are you?” Danny asked. “And why should we listen to you?”
“It’s none of your business who we are. And if you don’t listen, you’ll be in trouble!”
Danny paid no attention to the warning. Instead, he revved up his engine and pulled away from the other craft. Obviously the two men did not know what to do next, so they followed the young people around the island.
Bess had scanned the shoreline through binoculars as unobtrusively as possible. She focused on a metal tube sticking out of the water. It seemed to give off bursts of light, as if it were studded with prisms and mirrors reflecting the rays of the sun.
“Hey, see that thing over there? I wonder what it is!” she said, excited.
The others looked and George gasped. “It could be the periscope of a submarine!”
“What!” Danny exclaimed. For a moment he forgot to keep his engine racing.
Nancy took the binoculars from Bess and trained them on the strange object. “Is the water deep enough for a submarine to get in?”
“Yes,” Danny replied, “Notice that the thing is sticking out of one of the channels where the water is green. That means it’s deep enough for a small sub. As a matter of fact, during World War II enemy subs got in here this way. The government had mined all the larger, more important channels to keep them out, but small enemy craft slipped in anyway.”
“Danny, can you go into the channel?” Nancy asked. “I’d like to see if that really is a periscope.”
“Sure,” Danny said and changed course.
But they soon realized that the men on The Whisper had no intention of letting them go through with their plan.
“They’re coming closer,” George said tensely. “Obviously they don’t want us to check that thing out there.”