"

"But you'll be known, and if one of our men, or one who we suppose is
one, turns out to be a spy, he'll be very cautious while you're in
there."

"He won't know me," Tom said. "This is how I'll work it. I'll go off
with Professor Bumper the next time he starts on one of his weekly
expeditions into the woods. But I won't go far until I turn around and
come back. I'll adopt some sort of disguise, and I'll apply to you for
work. You can tell Tim to put me on. You might let him into the secret,
but no one else."

A few days later Tom was seen departing with Professor Bumper into the
interior, presumably to help look for the lost city. Mr. Damon was away
from camp on business connected with the drug concern, and Koku, to his
delight, had been given charge of a stationary hoisting engine outside
the tunnel, so he would not come in contact with Tom. It was not
thought wise to take the giant into the secret.

Then one day, shortly after Professor Bumper and Tom had disappeared
into the forest, a ragged and unkempt white man applied at the tunnel
camp for work. There was just the barest wink as he accosted Mr. Titus,
who winked in turn, and then the new man was handed over to Tim
Sullivan, as a sort of helper.

And so Tom Swift began his watch.

Chapter XVII

The Condor

Left to himself, with only the rather silent gang of Peruvian Indians
as company, Tom Swift looked about him. There was not much active work
to be done, only to see that the Indians filled the dump cars evenly
full, so none of the broken rock would spill over the side and litter
the tramway. Then, too, he had to keep the Indians up to the mark
working, for these men were no different from any other, and they were
just as inclined to "loaf on the job" when the eye of the "boss" was
turned away.

They did not talk much, murmuring among themselves now and then, and
little of what they said was intelligible to Tom. But he knew enough
of the language to give them orders, the main one of which was:

"Hurry up!"

Now, having seen to it that the gang of which he was in temporary
charge was busily engaged, Tom had a chance to look about him. The
tunnel was not new to him. Much of his time in the past month had been
spent in its black depths, illuminated, more or less, by the string of
incandescent lights.

"What I want to find," mused Tom, as he walked to and fro, "is the
place where those Indians disappeared. For I'm positive they got away