hree Americans to
pass on their way.

"And now where do you wish to go, Mr. Cushing?" Dave inquired, after
they had passed the British provost guard.

"I suppose you expect me to search for the thief," rejoined the man
from the State Department. "But that would now be worse than a waste
of time. Gibraltar, quaint Moorish city that it is, is so full of
holes in the wall that it would be impossible to find the thief, for
he will not venture out again to-night. The best thing I can do will
be to go straight to the American admiral, and you gentlemen, I
imagine, can take me there."

"A launch will put off from the mole for the flagship at ten
o'clock," Dave informed him. "We may as well go down to the mole and
wait."

Twice, on the way, after leaving the more crowded parts of the city
behind, the three were challenged by English sentries invisible in the
darkness.

"Who goes there?" came the sentry's hail in each instance.

"Officers from the American flagship," Darrin answered for the party.

"Pass on, gentlemen," came the response out of the darkness.

At all times strict watch over all comers outside the British army
service is kept at Gibraltar, and after dark this vigilance is
doubled.

"On a moonless night like this, one would imagine that Gibraltar, save
for the few blocks of 'city,' held few human beings," murmured Dan, as
the three continued on at a quiet walk toward the water front. "One
gets the impression that there are but a few sentries, sprinkled here
and there, yet we know there are thousands of British soldiers
scattered over this rock."

"Hardly scattered," smiled Dave Darrin. "Except for the guard, men and
officers are alike in barracks, and many of the barracks are at rather
long distances from the fortifications."

Nor are the fortifications to be found along the water front. Back on
the great hill of rock are gun embrasures, often cut into the face of
the rock itself. Back of the embrasures are galleries cut through the
stone, and here, in time of siege, the soldiers would stand behind the
huge guns.

Gibraltar's harbor is small, though large enough to hold a great
fleet. In the days when cannon had shorter range than now, a British
fleet might have hidden in the harbor and been secure against all the
fleets of the world, for the guns of the huge fortress could have sunk
the combined navies of the world, had they attempted to enter the
harbor. In these modern days Gibraltar is not so s