"Sure, I'll pump the bilge," a.s.sented Tom. "Just look here at the stuff slopping up through the floor boards," he continued. "It surely looks as if we'd lost some fuel."

"That's funny," declared Jack. "I wonder how it could have happened. The pipes were all right when we fitted out and nothing we have done since could have injured them."

A shout from Harry announced a discovery. He was backing out of the compartment under the pilot house floor and just forward of the engines.

As he appeared his face was the picture of rage.

"What's it?" queried Tom. "Don't hold your breath that way, you're apt to choke if you do," he laughed.

"Where is the fellow that opened that drain c.o.c.k?" shouted Harry shaking his fist in the air. "Someone deliberately drained our gasoline into the bilge. I found the drain c.o.c.k wide open!"

"n.o.body opened it," a.s.serted Jack. "We were all in the pilot house since dinner watching the fog and we couldn't reach the pipe."

"I hate to say it, Jack, but we were not all in the pilot house,"

answered Tom. "Maybe it isn't fair to the chap, but that fellow we nearly run over doesn't look good to me. I rather suspect him."

"Hush, my lad," Jack warned. "A good Boy Scout doesn't accuse anyone until he has proof, and we have no proof yet of his guilt."

"All right, Jack," unwillingly replied Tom, "but I can't help feel the way I feel, can I? He didn't impress me very favorably."

"And then, look at Rowdy!" put in Harry. "He spotted the fellow when he was still hanging on the cable and he tried to get back into the cabin all the time to eat up his visitor."

"Well, let's go back and wake him up and see what he knows," suggested Jack. "Maybe he can put up a good story that will satisfy even you chaps. I can hardly believe anyone would do a thing like that. He has no motive for attempting to cripple us like this."

The boys moved with one accord toward the after cabin. The Fortuna rolled viciously in the trough of the choppy sea, making their footing extremely unsteady. Jack swung open the door.

Starting back in amazement he b.u.mped into Tom who was following closely.

Harry was at their heels peering over their shoulders.

"Where is he?" gasped Jack wonderingly. "Where did he go?"

"The bird has flown!" declared Tom in a tragic tone.

"Bag and baggage!" a.s.serted Harry.

True enough, not a sign of the stranger remained except the pile of water soaked garments in which he had been clothed when first brought into the cabin. These lay in a heap on the floor.

"Maybe he's out on the after deck," ventured Jack still hopeful.

"Let's see," answered Tom. "If he is there, I'll cook and wash dishes and scrub decks for a week on end!"

The after deck was empty. The visitor was nowhere in sight.

"Well, it looks as if he had come up out of the sea like a modern Neptune and like Old Neptune has gone back into it again," Jack said, his voice shaking. You don't suppose the fright he had turned his head and made him commit suicide, do you?"

"Suicide your tintype!" stoutly scorned Tom. "Do you think that fellow would commit suicide in a rowboat?"

"What do you mean?" questioned Jack wonderingly.

"I mean that our young pirate friend got one perfectly good square meal of food, one entire new outfit of clothes and one rowboat from this bunch of kindergartners. Then he opened the drip c.o.c.k in our fuel tank and sneaked out the back door and is gone."

"Good night," vociferated Harry. "It's as clear as mud! Look at what that young villain has done! Why, he's a thief!"

"Easy now," admonished Jack. "We mustn't call him names. Maybe things look black for him, but it may come out all right."

"Yea-ah!" scorned Tom. "When I can see the back of my neck it will. That guy's crooked! That's what I believe."

"Me, too!" declared Harry. "I vote with Rowdy. He's usually pretty near right when it comes to reading character!"

"Well, anyhow, this won't get us anywhere, and the Fortuna is rolling like a loon. Let's see if Arnold can find bottom in the bilges yet and then we'll connect up the spare tank and start out."

"Second the motion," declared Tom. "We ought to get going."

Suiting the action to the word the boys returned to the cabin to find Arnold replacing the pump. The air was still heavy with the odor of gasoline but Jack deemed it safe to operate the engine, since the windows were to be left open giving a plentiful supply of air, thus preventing danger of an explosion.

Tom was about to replace the hood over the engines after they had been started when his eye caught sight of a piece of paper lying on the floor. Hastily he kicked it aside and was about to pa.s.s to the pilot house when Harry called his attention to the paper.

"Nice housekeeper you'd make," he taunted, "kick the dirt back under the couch and let the sweepers get it! Why don't you pick it up?"

"Guess I will," replied Tom shamefacedly. "I was in a hurry."

"What is it?" asked Harry. "Let me see it."

"Sure, read it," Tom answered. "Read it aloud and we'll all hear."

"What's this?" gasped Harry. "Listen, you fellows! Here's the secret of the whole thing! Hear this!"

"Well, read it," impatiently cried Arnold. "I'm dying to hear."

"Get the Fortuna and crew!" read Harry. "They know about the Spanish Chest. They're after it. Sink them if you have to."

As he finished reading he glanced at each of his chums in amazement.

Their faces were pictures of dismay and amazement.

"What does that mean?" Arnold cried in tones of wonder. "What does it mean when it says, 'Get the Fortuna and crew?'"

"The last part explains that," answered Jack. "It means that some one or more people are after us and will sink the Fortuna if they have to in order to 'get' us. It listens like desperate characters were following us all right. We must remember our motto, boys, and 'Be Prepared.' We know they're after us."

"Yes, 'Be Prepared' for what?" questioned Tom. "Who're after us and why?

What does that mean about the Spanish Chest?"

"I see it's time to let you fellows in on the whole thing," declared Jack. "I had hoped it would not be necessary to say anything for a long while yet for the moon isn't full until nearly a week from now, but this has precipitated matters. Now, listen!

"You all know Lawyer Geyer of Chicago. His offices are in the Masonic Temple. He and my father are very close friends--in fact they were schoolmates. Lawyer Geyer offered me a commission for him and fitted out this vessel and is paying our expenses. He also offered us half the reward if we were successful."

"What reward?" interrupted Arnold. "Why don't you hurry?"

"Keep still, rattle-head!" admonished Tom. "He's hurrying."