the village, and had lately been seen by Tom, riding around in a powerful auto. The sight of Andy did not make the young inventor feel any happier.

"Well, Tom, I think that will do," remarked Mr. Damon when, after about an hour's work, they had jointly written a letter to the African missionary.

"We've asked him enough questions, anyhow," agreed the lad. "If he answers all of them we'll know more about the city of gold, and where it is, than we do now."

"Exactly," spoke the odd man. "Now to mail the letter, and wait for an answer. It will take several weeks, for they don't have good mail service to that part of Africa. I hope Mr. Illingway sends us a better map."

"So do I," assented Tom. "But even with the one we have I'd take a chance and look for the underground city."

"I'll mail the letter," went on Mr. Damon, who was as eager over the prospective adventure as was Tom. "I'm going back home to Waterfield I think. My wife says I stay here too much."

"Don't be in a hurry," urged Tom. "Can't you stay to supper? I'll take you home to-night in the sky racer. I want to talk more about the city of gold, and plan what we ought to take with us to Mexico."

"All right," agreed Mr. Damon. "I'll stay, but I suppose I shouldn't. But let's mail the letter."

It was after supper, when, the letter having been posted, that Tom, his father and Mr. Damon were discussing the city of gold.

"Will you go, even if Mr. Illingway can't send a better map?" asked Mr. Damon.

"Sure," exclaimed Tom. "I want to get one of the golden images if I have to hunt all over the Aztec country for it."

"Who's talking of golden images?" demanded a new voice, and Tom looked up quickly, to see Ned Newton, his chum, entering the room. Ned had come in unannounced, as he frequently did.

"Hello, old stock!" cried Tom affectionately. "Sir, there's great news. It's you and me for the city of gold now!"

"Get out! What are you talking about?"

Then Tom had to go into details, and explain to Ned all about the great quantity of gold that might be found in the underground city.

"You'll come along, won't you, Ned?" finished the young inventor. "We can't get along without you. Mr. Damon is going, and Eradicate too, I guess. We'll have a great time."

"Well, maybe I can fix it so I can go," agreed Ned, slowly, "I'd like it, above all things. Where did you say that golden city was?"

"Somewhere about the central part of Mexico, near the city of--"

"Hark!" suddenly exclaimed Ned, holding up a hand to caution Tom to silence.

"What is it?" asked the young inventor in a whisper.

"Some one is coming along the hall," replied Ned in a low voice.

They all listened intently. There was no doubt but that some one was approaching along the corridor leading to the library where the conference was being held.

"Oh, it's only Mrs. Baggert," remarked Tom a moment later, relief showing in his voice. "I know her step."

There was a tap on the door, and the housekeeper pushed it open, for it had been left ajar. She thrust her head in and remarked:

"I guess you've forgotten, Mr. Swift, that Andy Foger is waiting for you in the next room. He has a letter for you."

"Andy Foger!" gasped Tom. "Here."

"That's so, I forgot all about him!" exclaimed Mr. Swift jumping up. "It slipped my mind. I let him in a while ago, before we came in the library, and he's probably been sitting in the parlor ever since. I thought he wanted to see you, Tom, so I told him to wait. And I forgot all about him. You'd better see what he wants."

"Andy Foger there--in the next room," murmured Tom. "He's been there some time. I wonder how much he heard about the city of gold?"

Chapter III Andy Is Whitewashed

The parlor where Mr. Swift had asked Andy to wait, adjoined the library, and there was a connecting door, over which heavy curtains were draped. Tom quickly pulled them aside and stepped into the parlor. The connecting door had been open slightly, and in a flash the young inventor realized that it was perfectly possible for any one in the next room to have heard most of the talk about the city of gold.

A glance across the room showed Andy seated on the far side, apparently engaged in reading a book.

"Did you want to see me?" asked Tom sharply. His father and the others in the library listened intently. Tom wondered what in the world Andy could want of him, since the two were never in good tame, and Andy cherished a resentment even since our hero had rescued him from the African jungle.

"No, I didn't come to see you," answered Andy quickly, laying aside the book and rising to face Tom.

"Then what--"

"I came to see your father," interrupted the red-haired bully. "I have a letter for him from my father; but I guess Mr. Swift misunderstood me when he let me in."

"Did you tell him you wanted to see me?" asked Tom suspiciously, thinking Andy had made a mistatement in order to have a longer time to wait.

"No, I didn't, but I guess your father must have been thinking about something else, for he told me to come in here and sit down. I've been waiting ever since, and just now Mrs. Baggert passed and saw me. She--"

"Yes, she said you were here," spoke Tom significantly. "Well, then it's my father you want to see. I'll tell him."

Tom hurried back to the library.

"Dad," he said, "it's you that Andy wants to see. He has a letter from Mr. Foger for you."

"For me? What in the world can it be about? He never wrote to me before. I must have misunderstood Andy. But then it's no wonder for my head is so full of my new gyroscope plans. There is a certain spring I can't seem to get right--"

"Perhaps you'd better see what Andy wants," suggested Mr. Damon gently. He looked at Tom. They were both thinking of the same thing.

"I will," replied Mr. Swift quickly, and he passed into the library.

"I wonder how much Andy heard?" asked Ned, in a low voice.

"Oh, I don't believe it could have been very much," answered Tom.

"No, I stopped you just in time," rejoined his chum, "or you might have blurted out the name of the city near where the buried gold is."

"Yes, we must guard our secret well, Tom," put in Mr. Damon.

"Well, Andy couldn't have known anything about the letter I got," declared Tom, "and if he only heard snatches of our talk it won't do him much good."

"The only trouble is he's been there long enough to have heard most of it." suggested Ned. They could talk freely now, for in going into the parlor Mr. Swift had tightly closed the door after him. They could just hear the murmur of his voice speaking to Andy.

"Well, even if he does guess about the city of gold, and its location, I don't believe he'll try to go there," remarked Tom, after a pause.

A moment later they heard Mr. Swift letting Andy out of the front door, and then the inventor rejoined his son and the others. He held an open letter in his hand.

"This is strange--very strange," he murmured.

"What is it?" asked Tom quickly.

"Why. Mr. Foger has written to me asking to be allowed to sell some of our patents and machines on commission."

"Sell them on commission!" exclaimed his son. "Why does a millionaire like Mr. Foger want to be selling goods on commission? It's only a trick!"

"No, it's not a trick," said Mr. Swift slowly. "He is in earnest. Tom, Mr. Foger has lost his millions. His fortune has been swept away by unfortunate investments, he tells me, and he would be glad of any work I could give him. That's why Andy brought the letter to-night. I just sent him back with an answer."

"What did you say, dad?"

"I said I'd think it over."

"Mr. Foger's millions gone," mused Tom.

"And Andy in there listening to what we said about the city of gold," added Ned. "No wonder he was glad the door was open. He'd be there in a minute, Tom, if he could, and so would Mr. Foger, if