"Bless my overshoes! I hope we're not sinking!" cried Mr. Damon, as he struggled into some of his clothes, an example followed by Ned and Tom.

"This boat has water-tight compartments, and if it does sink it won't do it in a hurry," commented Tom.

"I don't care to have it do it at all," declared Ned, who found that he had started to get into his trousers hindside before and he had to change them. "Think of all our baggage and supplies and the balloon on board." For the travelers had shipped their things by the same steamer as that on which they sailed.

"Well, let's get out and learn the worst," cried Tom.

He was the first to have the stateroom, and as he rushed along the passages which were now brilliant with light he saw other half-clad passengers bent on the same errand as himself, to get on deck and learn what had happened.

"Wait, Tom!" called Ned.

"Come along, I'm just ahead of you," yelled his chum from around a corner. "I'm going to see if Eradicate is up. He's an awful heavy sleeper."

"Bless my feather bed! That shock was enough to awaken anyone!" commented Mr. Damon, as he followed Ned, who was running to catch up to Tom.

Suddenly a thought came to our hero. The mysterious passengers in Stateroom No. 27! Surely this midnight alarm would bring them out, and he might have a chance to see who they were.

Tom thought quickly. He could take a turn, go through a short passage, and run past the room of the mysterious passengers getting on deck as quickly as if he went the usual way.

"I'll go look after Rad!" Tom shouted to Ned. "You go up on deck, and I'll join you."

Eradicate's stateroom was on his way, after he had passed No. 27. Tom at once put his plan into execution. As he ran on, the confusion on deck seemed to increase, but the lad noted that the vessel did not pitch and roll so much, and she seemed to be on an even keel, and in no immediate danger of going down.

As Tom neared Stateroom No. 27 he heard voices coming from it, voices that sent a thrill through him, for he was sure he had heard them before.

"Where are the life preservers? Oh, I know we'll be drowned! I wish I'd never come on this trip! Look out, those are my pants you're putting on! Oh, where is my collar? Hand me my coat! Look out, you're stepping on my fingers!"

These were the confused and alarmed cries that Tom heard. He paused for a moment opposite the door, and then it was suddenly flung open. The lights were glaring brightly inside and a strange sight met the gaze of the young inventor.

There stood Mr. Foger and beside him--half dressed--was his son-- Andy! Tom gasped. So did Andy and Mr. Foger, for they had both recognized our hero.

But how Mr. Foger had changed! His moustache was shaved off, though in spite of this Tom knew him. And Andy! No longer was his hair red, for it had been dyed a deep black and glasses over his eyes concealed their squint. No wonder the purser had not recognized them by the descriptions Tom and Ned had given.

"Andy Foger!" gasped Tom.

"Tom--it's Tom Swift, father!" stammered the bully.

"Close the door!" sharply ordered Mr. Foger, though he and his son had been about to rush out.

"I won't do it!" cried Andy. "The ship is sinking and I'm not going to be drowned down here."

"So it was you--after all," went on Tom. "What are you doing here?"

"None of your business!" snapped Andy. "Get out of my way, I'm going on deck."

Tom realized that it was not the proper time to hold a conversation, with a possibly sinking ship under him. He looked at Mr. Foger, and many thoughts shot through his mind. Why were they on board? Had it anything to do with the city of gold? Had Andy overheard the talk? Or was Mr. Foger merely looking for a new venture whereby to retrieve his lost fortune.

Tom could not answer. The bully's father glared at our hero and then, slipping on a coat, he made a dash for the door.

"Get out of my way!" he shouted, and Tom stood aside.

Andy was already racing for the deck, and as the noise and confusion seemed to increase rather than diminish, Tom concluded that his wisest move would be to get out and see what all the excitement was about.

He stopped on his way to arouse Eradicate but found that he and all the colored persons had left their staterooms. A few seconds later Tom was on deck.

"It's all right, now! It's all right!" several officers were calling. "There is no danger. Go back to your staterooms. The danger is all over."

"Is the ship sinking?"

"What happened?"

"Are we on fire?"

"Are you sure there's no danger?"

These were only a few of the questions that were flying about, and the officers answered them as best they could.

"We hit a derelict, or some bit of wreckage," explained the first mate, when he could command silence. "There is a slight hole below the water-line, but the bulkheads have been closed, and there is not the slightest danger."

"Are we going to turn back for New York?" asked one woman.

"No, certainly not. We're going right on as soon as a slight break to one of the engines can be repaired. We are in no danger. Only a little water came in before the automatic bulkheads were shut. We haven't even a list to one side. Now please clear the decks and go back to bed."

It took more urging, but finally the passengers began to disperse. Tom found Ned and Mr. Damon, who were looking for him.

"Bless my life preserver!" cried the odd man. "I thought surely this was my last voyage, Tom!"

"So did I," added Ned. "What's the matter, Tom, you look as though you'd seen a ghost."

"I have--pretty near. The Fogers are on board."

"No! You don't mean it!"

"It's a fact. I just saw them. They are the mysterious passengers." And Tom related his experience.

"Where are they now?" demanded Ned, looking about the deck.

"Gone below again, I suppose. Though I don't see what object they can have in concealing their identity any longer."

"Me either. Well, that surely is a queer go."

"Bless my hot cross buns! I should say so!" commented Mr. Damon when he heard about it. "What are you going to do, Tom?"

"Nothing. I can't. They have a right on board. But if they try to follow us--well, I'll act then," and Tom shut his jaws grimly.

Our three trends went back to their state-room, and Eradicate also retired. The excitement was passing, and soon the ship was under way again, the sudden shock having caused slight damage to one of the big engines. But it was soon repaired and, though the storm still continued, the ship made her way well through the waves.

A stout bow, water-tight compartments, and the fact (learned later) that she had struck the derelict a glancing blow, had combined to save the Maderia.

There were many curious ones who looked over the side next morning to see the gaping hole in the bow. A canvas had been rigged over it, however, to keep out the waves as much as possible, so little could be viewed. Then the thoughts of landing occupied the minds of all, and the accident was nearly forgotten. For it was announced that they would dock early the next morning.

In spite of the fact that their presence on board was known to Tom and his friends, the Fogers still kept to their stateroom, not even appearing at meals. Tom wondered what their object could be, but could not guess.

"Well, here we are at last--in Mexico," exclaimed Ned the next morning, when, the Maderia having docked, allowed the passengers to disembark, a clean bill of health having been her good luck.

"Yes, and now for a lot of work!" added Tom. "We've got to see about getting ox teams, carts and helpers, and no end of food for our trip into the interior."

"Bless my coffee pot! It's like old times to be going off into the jungle or wilderness camping," said Mr. Damon.

"Did you see anything of the Fogers?" asked Ned of his chum.

"Not a thing. Guess they're in their stateroom, and they can stay there for all of me. I'm going to get busy."

Tom and his friends went to a hotel, for they knew it would take several days to get their expedition in shape. They looked about for a sight of their enemies, but saw nothing of them.

It took five days to hire the ox carts, get helpers, a supply of food and other things, and to unload the balloon and baggage from the ship. In all this time there was no sign of the Fogers, and Tom hoped they had gone about their own business.

Our friends had let it be known that they were going into the interior to prospect, look for historic relics and ruins, and generally have a sort of vacation.

"For if it is even hinted that we are after the city of gold," said Tom, "it would be all up with us. The whole population of Mexico would follow us. So keep mum, everyone."

They all promised, and then they lent themselves to the task of getting things in shape for travel. Eradicate was a big help, and his cheerful good nature often lightened their toil.

At last all was in readiness, and with a caravan of six ox carts (for the balloon and its accessories took up much space) they started off, the Mexican drivers cracking their long whips, and singing their strange songs.

"Ho, for the interior!" cried Ned gaily.

"Yes, we're off into the unknown all right," added Tom grimly, "and there's no telling when we'll get back, if we ever will, should the head-hunters get after us."

"Bless my collar and tie! Don't talk that way. It gives me the cold shivers!" protested Mr. Damon.