"You may get into trouble."

"Oh, I guess not. If I do I can stand it. I want to solve this mystery." Tom did put his question to one of the dining saloon stewards and it created no suspicions.

"Ah, yes, I guess you must mean Mr. Wilson and his son." spoke the steward when he had referred to a list that corresponded with the numbers of the vacant places at the table. "They have their meals served in their stateroom."

"Why?" asked Tom, "are they ill?"

"I really couldn't say, sir. They prefer it that way, and the captain consented to it from the first."

"But I should think they'd want to get out for a breath of air," put in Ned. "I can't stay below decks very long."

"They may come out at night," suggested the steward. "Some of our travelers think they are less likely to be seasick if they come out at night. They don't see the motion of the waves then."

"Guess that's it," agreed Tom with a wink at Ned. "Much obliged.

Glad we're not seasick," and he linked his arm in that of his chum's and marched him off.

"Why the wink?" asked Ned, when they were out of earshot of the steward.

"That was to tip you off to say nothing more. I've got a plan I'm going to work."

"What is it?"

"Well, we know who the mysterious ones are, anyhow--at least we know their names--Wilson."

"It may not be the right one."

"That doesn't make any difference. I can find out their stateroom by looking at the pa.s.senger list."

"What good will that do."

"Lots. I'm going to keep a watch on that stateroom until I get a good look at the people in it. And if they only come out at night, which it begins to look like, I'm going to do some night watching.

This thing has got to be settled, Ned. Our trip to the city of gold is too important to risk having a mysterious couple on our trail--when that same couple may be the Fogers. I'm going to do some detective work, Ned!"

CHAPTER XI

THE MIDNIGHT ALARM

"Whew! What a lot of 'em!"

"Bless my fish line! It's a big school!"

"Look how they turn over and over, and leap from the water."

"By golly, dere is suttinly some fish dere!"

These were the exclamations made by our four friends a few days later, as they leaned over the rail of the Maderia and watched a big school of porpoises gamboling about in the warm waters of the gulf stream. It was the second porpoise school the s.h.i.+p had come up with on the voyage, and this was a much larger one than the first, so that the pa.s.sengers crowded up to see the somewhat novel sight.

"If they were only good eating now, we might try for a few,"

observed Ned.

"Some folks eat them, but they're too oily for me," observed a gentleman who had struck up an acquaintance with the boys and Mr.

Damon. "Their skin makes excellent shoe laces though, their oil is used for delicate machinery--especially some that comes from around the head, at least so I have heard."

"Wow! Did you see that?" cried Tom, as one large porpoise leaped clear of the water, turned over several times and fell back with a loud splash. "That was the biggest leap yet."

"And there goes another," added Ned.

"Say, this ought to bring those two mysterious pa.s.sengers out of their room," observed Tom to his chum in a low voice. "Nearly everyone else seems to be on deck."

"You haven't been able to catch a glimpse of them; eh Tom?"

"Not a peak. I stayed up several nights, as you know, and paced the deck, but they didn't stir out. Or, if they did, it must have been toward morning after I turned in. I can't understand it. They must be either criminals, afraid of being seen, or they ARE the Fogers, and they know we're on to their game."

"It looks as if it might be one or the other, Tom. But if they are criminals we don't have to worry about 'em. They don't concern us."

"No, that's right. Split mackerel! Look at that fellow jump. He's got 'em all beat!" and Tom excitedly, pointed at the porpoises, the whole school of which was swimming but a short distance from the steamer.

"Yes, a lot of them are jumping now. I wonder--"

"Look! Look!" cried the man who had been talking to Mr. Damon.

"Something out of the ordinary is going on among those porpoises. I never saw them leap out of the water like that before."

"Sharks! It's sharks!" cried a sailor who came running along the deck. "A school of sharks are after the porpoises!" "I believe he's right," added Mr. Sander, the gentleman with Mr. Damon. "See, there's the ugly snout of one now. He made a bite for that big porpoise but missed."

"Bless my meat axe!" cried the odd man. "So he did. Say, boys, this is worth seeing. There'll be a big fight in a minute."

"Not much of a fight," remarked Mr. Sander. "The porpoise isn't built for fighting. They're trying to get away from the sharks by leaping up."

"Why don't they dive, and so get away?" asked Ned.

"The sharks are too good at diving," went on Mr. Sander. "The porpoises couldn't escape that way. Their only hope is that something will scare the sharks away, otherwise they'll kill until their appet.i.tes are satisfied, and that isn't going to be very soon I'm afraid."

"Look! Look!" cried Ned. "A shark leaped half way out of the water then."

"Yes, I saw it," called Tom.

There was now considerable excitement on deck. Nearly all the pa.s.sengers, many of the crew and several of the officers were watching the strange sight. The porpoises were frantically tumbling, turning and leaping to get away from their voracious enemies.

"Oh, if I only had my electric rifle!" cried Tom. "I'd make some of those ugly sharks feel sick!"

"Bless my cartridge belt!" cried Mr. Damon. "That would be a good idea. The porpoises are such harmless creatures. It's a shame to see them attacked so."

For the activity of the sharks had now redoubled, and they were darting here and there amid the school of porpoises biting with their cruel jaws. The other fish were frantically leaping and tumbling, but the strange part of it was that the schools of sharks and porpoises kept about the same distance ahead of the s.h.i.+p, so that the pa.s.sengers had an excellent view of the novel and thrilling sight.

"Rifle!" said Mr. Sander, catching at the word. "I fancy the captain may have some. He's quite a friend of mine, I'll speak to him."