emanded the young lieutenant, wheeling quickly.

"What's the use of denying it," questioned the mate, "with such cargo as
we have?"

"Very little use indeed," Hal rejoined. "How much were you to get as
your share of the night's work?"

"Oho! I didn't say that I had even a suspicion of what the game was,"
retorted the mate coolly. "I could only suspect, at best. You can't trap
me into saying anything that would send me along to share Captain
Boggs's fate."

"You're smooth enough," nodded Lieutenant Overton, "but don't try to
play any further tricks."

"With United States troops aboard? What do you take me for?" grumbled
the mate.

Hal didn't feel much inclined to talk with the fellow, so he stepped
forward, leaving the mate by himself.

Half an hour passed. Truth to tell, the young Army officer felt the
monotony of his present position, confined to the boat and the pier.
Passing the sentry at the gang-plank, who stood at present arms in
salute, Hal Overton walked forward to the outer end of the pier. He had
stood there some ten minutes, when, two or three miles up the river, he
thought he saw a brief flash.

"That might have come from a search-light, swiftly operated," thought
Lieutenant Hal, with a start. After a moment's reflection, he hurried on
board the boat.

"Mate," he directed, "shove off and steam out just past the end of the
pier."

"Why----" began the mate wonderingly.

"Obey the order, sir!"

As the boat moved slowly into open water Hal, standing by the
search-light, gave another order:

"Switch on this light, mate."

"But your captain said----"

"Switch on the light, man! Be quick about it!"

As the light gleamed out Lieutenant Hal turned its broad flare up the
river. Just on the edge of the beam he picked up a motor boat of
considerable size. The other craft was some three miles up the river,
headed due south across to the Mexican border.

In the instant that the man in charge of the motor boat discovered the
search-light, he crowded on more speed.

"My plain orders are to remain here," quivered Lieutenant Hal to
himself. "If I obey, even during a five minutes' delay, that craft will
outfoot us to Mexico, and a cargo of arms will be on the other shore.
There's no time to communicate with Captain Foster. What on earth shall
I do--disobey and face the chance of trial for disobedience of orders?"

CHAPTER XVI

AFTER SWIFT GAME

It was a ticklish position, and one that call