"I've posted a corporal and a guard to see that none of the boats leave shore until they've been found to contain no freight that looks like munitions of war. To my surprise none of the Mexicans showed the slightest interest in my doings. It begins to look as though they have no intention of trying to ferry arms over the frontier at present." "Are there any steam craft at this point, sir?" inquired Lieutenant Hal. "Nothing of the sort, Mr. Overton." "Then, if the Mexicans do plan to get any war supplies over the frontier, don't you imagine that they have arranged for a launch or a tug to drop down the river, or come up the stream, from some other point?" "That's worth thinking of," muttered the captain, looking thoughtful. "A boat engaged in such secret work would probably also take the risk of running without lights." "But a steamer would be bound to make noise enough to give us warning when she attempted to come in toward the shore," pursued Captain Foster. "That, sir, will depend on how far apart our guards are to-night, or on such other night as the Mexicans may make the attempt." "Now that our troops are here they may make no attempt," hinted Noll. "They will if they dare," replied Captain Foster. "If there are six hundred rifles in Guarez's barn, and more elsewhere, then there must be a lot of Mexicans on the other side waiting impatiently for the supplies to reach them. Your suggestion, Mr. Overton, about a steamer, is one that must be kept in mind." After some thought Captain Foster wrote a telegram, entrusting it to a corporal to take over to the village. Hal was then directed to take sixty men and to dispose of them in suitable spots along the water-front. Fifty men were to be used for this purpose. A corporal and three men would then patrol along the easterly end of the line, Hal and the few remaining men of his command patroling the western end of the line. Either patrol would be quick to respond to any shot from a sentry. "This is an exceedingly responsible task, Mr. Overton," Captain Foster informed the young officer. "If you fail at some point, then arms enough to equip a brigade of Mexican rebels may cross the river to-night." "I shall keep every sense on the alert, sir." Noll was given command of the camp. Captain Foster, now thoroughly fagged, turned in for a few hours' sleep, after leaving orders to be called at eleven o'clock. "You will find me prowling about your lines from midnight on, Mr. Overton," was the captain's last word before turning in. "It is now nearly dark, so I suggest that you march your men without any unnecessary delay." Two minutes later Lieutenant Hal was marching his command from camp. He did not take his column through the village. Instead, he marched it to the eastward, then over to the river bank.