"That's right," Nancy told him and explained exactly what had happened. "We're on our way to visit Mr. and Mrs. Henry Cosgrove, but we don't know how to find the place."

"I'll order a cab for you," the officer said, and asked his companion to make the call. "I know the Cosgroves," he continued. "It's a long ride from here."

He took a notebook from his pocket and wrote down the circ.u.mstances of the kidnapping. First he requested the names and addresses of the girls. This time Nancy gave him the correct ones. She described Steven, the young man who had met them at the airport, as well as the couple who had locked them into the bedrooms.

"We'll get to work on the case at once," the officer promised.

He walked to the squad car and picked up his radio phone. First he asked that a taxi be sent out, then gave a full report on the case. When he returned to the girls, he said, "A cab will be here in a few minutes. Is this your first visit to Key Biscayne?"

When the three nodded yes, he shook his head. "I'm sorry your introduction to our town was so disastrous. Believe me, you'll find that Key Biscayne is a mighty nice area. Well, I hope you'll have an enjoyable time while you're here."

In a few minutes a taxi pulled up in front of the house. The driver looked at the girls curiously.

Bess explained they had walked through the swamp after coming from the wrong direction to the Cosgroves' home. She gave the correct address and they set off.

Unlike the couple who tried to kidnap them, Helen and Henry Cosgrove were delightful. Nancy quickly explained why they were so unkempt.

"What a dreadful experience!" Mrs. Cosgrove exclaimed. "We must report it to the police at once!"

"I've already done that," Nancy said, and told the whole story.

Mr. Cosgrove said, "I got to the airport late because our car wouldn't start. When I arrived, you had already gone. I thought you might have taken a taxi and come back home. We started to worry when you didn't arrive. I even called your home in River Heights, but no one was there."

"Good," Nancy said with a chuckle. "Dad and Hannah didn't have a chance to become alarmed."

At this point a sixteen-year-old boy with red hair and twinkling eyes walked in and was introduced to the girls as Danny Cosgrove. He looked at their dirty shoes and clothes and said, "I guess you got here the hard way. What happened?"

Nancy told him and he responded, "Your dad said you would be here to solve a mystery and there might be some danger connected with it. You sure made a good start!"

The girls laughed, then asked to be excused to change their clothes. Mrs. Cosgrove led them to two bedrooms. "Who wants to share the big one?" she asked.

Bess and George said they would, so Nancy took the smaller room.

During dinner Nancy explained more about the mystery, but asked the Cosgroves to keep it a secret. "We decided to use fake names to avoid detection by any suspects," Nancy said. "But now I'm not so sure it's worth it."

Mrs. Cosgrove spoke. "I'd try it if I were you. Even if part of this group you're about to investigate knows who you are, not everyone connected with the Crocodile Ecology Company has seen you. By using fict.i.tious names, you can probably fool them."

"What are your new names?" Danny asked.

"I'm Anne," said Nancy.

"And I'm Elizabeth," Bess replied.

George grinned. "I'm Jackie."

Nancy's first bit of detective work was to call the police early next morning. She inquired about the house where they had been imprisoned and was told that the owners were away on vacation.

The girls' kidnappers had broken in and "borrowed" the premises for their scheme. The police managed to track down Steven, who told them the couple had approached him in a supermarket and asked him if he would like to earn some money. They needed someone to pick up three visitors from the airport and bring them to their house.

"Steven agreed and a.s.sured as he knew nothing about a kidnapping," the officer concluded. "We're inclined to believe his story, but we'll keep an eye on him."

After Nancy had put down the phone, Mr. Cosgrove asked the girls if they would like Danny to take them to Crocodile Island in the family's motorized skiff.

"It's high tide now and a good time to go," he said. "I wish you luck in your sleuthing," he added, smiling.

"Thank you very much," Nancy said. "Do you think we'll have a chance to go on the island?"

"Sometimes they do allow visitors," Mr. Cosgrove explained. "On certain days of the week, but I don't know about today. You'll have to see."

The four walked to the marina where the boat was kept.

"How do you like the name I gave it?" Danny asked.

The girls laughed when they saw what was painted on the side of the skiff.

"Pirate!" George exclaimed. "Even if you hadn't told me, I'd have known a boy picked it." George exclaimed. "Even if you hadn't told me, I'd have known a boy picked it."

"Do you go after all the treasure that's supposed to be buried on these islands?" Bess asked him.

"I sure do," Danny replied. "The trouble is, some of the small keys floated away in hurricanes and any treasure on them is lost forever."

"What a shame!" George teased. "And here we came all the way to Florida, thinking we could dig up a million doubloons!"

The young people laughed, then stepped aboard the skiff. Four swivel chairs were bolted to the deck, and Danny explained that this made it easy for fishermen to turn in all directions. Then he pointed to the large outboard motor in the rear of the craft. "It weighs two hundred and fifty pounds and is raised and lowered hydraulically."

"Why do you have to raise it?" Bess asked.

"When you get caught in low tide, you literally have to jump along over the sand dunes at a very fast clip. If you don't, you're apt to get stuck."

Danny settled himself behind the wheel and started the boat. As they rode along, he pointed out the sh.o.r.eline of Key Biscayne with its high-rise condominiums and many-storied hotels. But soon they left the area and one little island after another came into view.

"All of these were built up by coral formations and mangrove trees," Danny explained. "I'll show you some trees along the edge. The way they grow is fascinating."

He pulled up to a small key and stopped the boat. The narrow mangrove trunks rose some fifteen feet into the air, then started to bend over. Their branches were heavy with leaves, which in turn hung down into the water. Being thick and close together, they were a natural catchall for whatever floated by, and together they formed a solid sh.o.r.eline.

"Over there," said Danny, pointing, "Is a place where the water is a little deeper. We can glide in between two of the wide-spreading trees and you can get a better look."

He raised the outboard motor somewhat, moved the skiff forward, then headed among the mangroves. It was a strange sight. Roots twisted and turned. Among them and beyond the sh.o.r.eline lay fragments of weathered coral rock.

Suddenly there was a grinding sound under the skiff, which stopped so abruptly it almost threw the girls into the water!

CHAPTER IV.

Crocodile Farm.

"WHAT did we hit?" Bess cried out. "Oh, I hope it didn't ram a hole in the skiff!"

"I doubt it," Danny replied. From the deck, he picked up a long pole with a p.r.o.nged hook on the end. Leaning over the side, he poked around under the boat and raised an enormous pile of matted mangrove roots and leaves. With a chuckle, he swung it into the skiff.

"Ugh!" Bess cried out. "What are all those crawly things in there?"

"Crocodile food," Danny said and handed her a, tin can. "Pick them up and drop them in this."

George laughed. "You asked the wrong person, Danny. Bess hates that kind of thing."

"You bet I do," Bess said, pulling her knees up to her chin.

Nancy took the can and she and George scooped up the small marine creatures. Some of them were no longer than a half inch.

Nancy remarked, "A crocodile would have to eat a million of these to get even half a meal."

"That would do for a snack," Danny agreed. Then he made sure the outboard motor was not dogged.

Fortunately the green ma.s.s had come up in one big lump, and he was able to back the skiff away from the key. George threw the leaves and roots far out and once more the boat headed for Crocodile Island. The water was very shallow, and sand dunes stuck up here and there. Once in a while the skiff ran through an area where the water was dark green in color.

"These channels run quite deep," Danny explained. "Larger craft can travel only in these, whereas a flat-bottomed boat like ours can go anywhere on the bay."

A few minutes later he pointed to their left, where series of tall, stout poles protruded from the water. Many had small cottages on top.

"I've never seen anything like this before," Bess stated. "Are they summer homes?"

Danny nodded. "Right. They're weekend retreats. The owners like to get away from the city. Out here there are a lot of interesting things to see, and many birds. But not noise except from the boat motors."

"What about the poles with nothing on top?" George asked.

"The houses they supported were blown away in hurricanes," Danny explained.

Bess shivered. "I'd run at the first sign of a breeze if I lived in one of them."

Danny laughed. "I'm sure people don't stay and wait for the storm."

An hour later he reached another key. It was surrounded by a line of mangroves. As they drew closer, the girls saw stakes driven into the water, forming a fence. It stretched as far as they could see. Here and there warning signs were posted:

CROCODILE FARM.

NO TRESPa.s.sING UNDER PENALTY OF THE LAW.

"So this is Crocodile Island," George remarked.

Just then Nancy noticed two bright spots in the water behind the fence. "What are those?" she asked.

"Crocodile eyes," Danny told her. "You see, these reptiles can stay completely under water except for their eyes, which are raised high in their heads. Watch!" He picked up the can of little marine creatures and tossed them toward the crocodile. Its great jaws rose and took in the food. Then the reptile swam away lazily.

Bess, who had drawn her feet back on deck, said, "I see now why the owners put up this fence. They left enough water between it and the island so the crocodiles can enjoy themselves."

Danny told her that this was the first time he had ever seen one of the creatures in this spot "Usually they're kept in pits and guarded carefully," he added.

"Where's the entrance to the island?" Nancy questioned.

"On the far side of the key. You girls are lucky. Today is a visiting day."

There were several boats with tourists waiting to see Crocodile Island. A boardwalk ran from a small dock up through mangrove trees to a partially open area. Here, among the mangrove trees, were shallow pits fenced in with five-foot concrete walls.

Fresh sea water flowed into them through pipes. There was an elevated area in each pit so the reptiles could stay either in or out of the water.

A small Irish terrier ran around, barking loudly at the visitors.

"His name is E-fee," Danny explained. "I know because I've been here before."

"E-fee?" Bess asked. "That's a strange name."

"It's Seminole for 'dog,'" Danny said. "He has six toes on one front paw and likes to be the center of attention. He's always around on visiting days." The boy petted the little animal and E-fee licked his fingers.

A guide asked the group to follow him, and told them about the crocodiles. "The youngest ones have a greenish cast with black markings," he said. "The half-grown ones are olive green, and the senior citizens are all gray."

They came to an enclosure with a fifteen-foot-long giant in it. "This old fellow has to stay by himself," the guide said. "He doesn't seem to get along with the others. Does anyone have any questions?"

Danny spoke up. "I've heard that crocodiles can drown. Is that true?"

"It sure is," the guide replied. "Both alligators and crocodiles can stay under water until the oxygen in their lungs is used up-alligators longer than crocodiles. But finally they both have to surface."

"How often do they have to come up?" George asked.

"Oh, I'd say the crocs come up about once every hour. It depends on the water temperature. The warmer the water, the more often they have to breathe. In cold water they can hibernate a lot longer."

"Do they have to surface to eat?" a man inquired.

"Yes. They can seize their prey underwater, because they have valves in the backs of their throats that close when they open their mouths and the water can't flow into their lungs. But they have to stick their heads out to swallow."

The group walked on, and Nancy asked the guide, "What do you do with all these crocodiles?"

"The Ecology Company sells them to various zoos and parks and even to the government," he replied.

"The government?" George repeated. "What would Uncle Sam do with a lot of crocodiles?"