t."

He went out into the patio and looked up at the sun. It was
almost in the zenith and the air was stifling.

"Any one would be a fool to go out at this time of day," he
mused. "I wonder where the fellows are?"

He stepped back under the shade of the arcade that extended clear
around the patio and threw himself onto a stone seat.

"Queer old place," he thought, "and a queer old seat."

He laid his hand on one of the carved arms and mechanically toyed
with an eagle's head that formed one of the decorations. To his
surprise the head turned in his hand.

"I hope I haven't broken it," he said as he examined it more
closely.

It was clearly made to revolve and so he turned it clear around,
when of a sudden the arm of the seat fell apart and the bottom
collapsed, disclosing to Billie's astonished eyes a pair of
stairs.

Almost thrown to the pavement by the giving way of the seat,
Billie picked himself up and looked about to see if he were
observed.

There was no one in sight and he stooped down and examined the
stairs carefully. Then he straightened up and rubbed his chin as
a sudden gleam of intelligence passed through his brain.

"So," he muttered, "this is why Santiago dwells in a house that
is directly back of the banker's. That was his box and he is the
strange man who made the million-dollar deposit in Don Esteban's
bank."

Then he stopped and pondered.

"But who stole the box? Not Santiago, for he has not left his
room for days. If it was Strong, he must have entered the bank
from some direction other than this. I don't understand, but I'm
going to make some further investigation."

He reentered his room, buckled on his automatic and took from his
suit case--which, by the way, he had located at the railway
station along with that of his companions after the occupation of
the city by the marines--his electric torch. Then he went out and
descended the stairs, which he discovered were twenty-four in
number.

Reaching the bottom he found himself upon a landing some six or
eight feet square, from the opposite side of which another flight
of stairs ascended.

"I reckon I better see where they lead to," was his comment as he
slowly began their ascent.

After going up eighteen stairs his head touched the floor above.
He counted the remaining steps by the light of his torch and
found that there were six more. This would make the floor over
his head on an exact level with the floor of Santiago's house