“I wonder what he wants?” spoke Tom, as he noted the approaching figure.

“Probably he’s going to suggest that we take a few days’ vacation,” ventured Ned.  “He doesn’t like work.”

“Senor,” began Delazes addressing Tom, who called to Eradicate to bring his oxen to a halt, “are you aware that we are being followed?”

“Followed?  What do you mean?” cried the young inventor, looking quickly around.

“Bless my watch chain!” gasped Mr. Damon.  “Followed?  By whom?” He, too, looked around, as did Ned, but the path behind them was deserted.

“When last we doubled on our own trail, to make the ascent of the big hill a little easier,” on the Mexican, “I saw, on the road below us two ox carts, such as are hired out to prospectors or relic seekers like yourself.  At first I thought nothing of it.  That was early this morning.  When we stopped for dinner, once more having to double, I had another view of the trail, I saw the same two carts.  And now, when we are about to camp, the same two carts are there.”

He pointed below, for the caravan was on quite an elevation now, and down on the faint trail, which was in plain view, for it wound up the mountain like a corkscrew, were two ox carts, moving slowly along.

“They are the same ones,” went on Delazes, “and they have been following us all day—­perhaps longer—­though this is the first I have noted them.”

“Followed!” murmured Tom.  “I wonder—­” -From his valise he took a small but powerful telescope.  In the fast-fading light he focused it on the two ox carts.  The next moment he uttered an exclamation of anger and dismay.

“Who is it?” asked Ned, though he was almost sure what the answer would be.

“Andy Foger and his father!” cried Tom.  “I might have known they’d follow us—­to learn—­” and then he stopped, for Senor Delazes was regarding him curiously.

CHAPTER XIV

A WEARY SEARCH

“Are you sure it’s them?” asked Ned.

“Bless my toothpick!” cried Mr. Damon.  “It isn’t possible, Tom?”

“Yes, it is,” said the young inventor.  “It’s the Fogers all right.  Take a look for yourself, Ned.”

The other lad did, and confirmed his chum’s news, and then Mr. Damon also made sure, by using the glass.

“No doubt of it,” the odd man said.  “But what are you going to do, Tom?”

Our hero thought for a moment.  Then, once more, he looked steadfastly through the glass at the other carts.  The occupants of them did not appear to know that they were under observation, and at that distance they could not have made out our friends without a telescope.  Tom ascertained that the Fogers were not using one.

“Has Senor Swift any orders?” asked Delazes.  “Who are these Fogers?  Enemies of yours I take it.  Why should they follow you merely to find a ruined city, that the ruins and relics may be studied?”