is tracks.

"It's a pity," he agreed, "that you forgot to mention that. As a rule,
when I give expert advice I get a fat check for it."

"And what's more," continued Roddy, "if Alvarez finds it out you'll go
to jail."

"Your piquant narrative interests me strangely," said McKildrick.
"What else happens to me?"

"But, of course," explained Roddy reassuringly, "you'll tell them you
didn't know what you were doing."

"How about _your_ telling me what we are doing?" suggested the
engineer.

"From this point," was Roddy's only reply, "you crawl on your hands
and knees, or some one may see you."

The engineer bent his tall figure and, following in Roddy's trail,
disappeared into the laurel bushes.

"Why shouldn't they see me?" he called.

"One looks so silly on his hands and knees," Roddy suggested.

For ten minutes, except for the rustle of the bushes, they pushed
their way in silence, and then Roddy scrambled over the fallen wall of
the fort, and pointed down at the entrance to the tunnel.

"The problem is," he said, "to remove these slabs from that
staircase, and leave it in such shape that no one who is foolish
enough to climb up here could see that they had been disturbed."

"Do you really think," demanded McKildrick, smiling sceptically, "that
there _is_ buried treasure under these stones?"

"Yes," answered Roddy anxiously, "a _kind_ of buried treasure."

Cautiously McKildrick raised his head, and, as though to establish his
bearings, surveyed the landscape. To the north he saw the city; to the
east, a quarter of a mile away, the fortress, separated from the
mainland by a stretch of water; and to the south, the wild mesquite
bushes and laurel through which they had just come, stretching to the
coast.

"Is this a serious proposition?" he asked.

"It's a matter of life and death," Roddy answered.

McKildrick seated himself on the flight of stone steps, and for some
time, in silence, studied them critically. He drove the heel of his
boot against the cement, and, with his eyes, tested the resistance of
the rusty bars of iron.

"With a couple of men and crowbars, and a pinch of dynamite that
wouldn't make a noise," he said at last, "I could open that in an
hour."

"Could you put it back again?" asked Roddy.

There was a long pause.

"I guess," said McKildrick, "you'll have to let me in on the ground
floor."

The sun had set and the air had turned cold and damp. Roddy seated
himself beside his c