The party moved along slowly and cautiously through the clumps of trees and mesquite-bushes, until some time during the afternoon, when they came to a bend in the river known as the Horseshoe, where was located the Mission Concepcion. "This is a strong position," said Colonel Bowie. "The river and timber will shelter us from behind, and in front is the bluff. It's an ideal place." "You are right," said Colonel Fannin. "General Austin cannot do better than bring the army here." The orders had been to return, if possible, before nightfall, but at this time in the year it grew dark rapidly, and it was decided to go into camp for the night; and outposts were accordingly stationed in all directions, that they might not be surprised. Although the Texans were not aware of it, the Mexican scouts had been watching them closely, and no sooner did the party go into camp than the enemy resolved to surround them in the darkness, and either shoot them all down, or take them prisoners. For this purpose General Cos sent out four hundred of his best troops, determined to teach the Texans a lesson that they should never forget. Lieutenant Radbury, as we must now call him, had charge of the outposts along the river, and, anxious to see that his men did their duty, he remained out with them, travelling slowly from one sentinel to another. On duty at one point was Stover, as alert as though after some big game. "Any alarm, Poke?" asked the lieutenant, in a whisper, for it was not known but that the Mexicans might be close at hand. "Yes, and no," answered the old frontiersman, slowly. "Perhaps my hearsight is deceivin' me, but I 'most reckoned as how I heard the creakin' o' wheels about--thar they go ag'in!" He broke off short, and held up his hand for silence. Both men listened intently, and from the river bank they heard the steady, lumbering creak as of heavy wagon wheels. "Am I right, leftenant?" demanded the frontiersman, when the sounds had come to an end. "You are, Poke; do you know what it was?" "Can't say exactly." "It was the creaking of artillery wheels." "Whoopee! Then they must be comin' over fer fair!" "Yes. I will report at once." Lieutenant Radbury lost no time in making his way to the tent in which Colonel Fannin was poring over an old map of San Antonio. "I have to report the coming of some artillery," he said, as he saluted. "Artillery?" repeated the commander. "Mexican artillery?" "I think so, colonel." And Lieutenant Radbury related as much as he knew. He had scarcely finished, when Colonel Bowie came in on the run. "They are starting to surround us!" he cried. "They are bringing over men and cannon!" The whole camp was soon in alarm, and, after a short talk among the officers, it was decided to bring up the men in a semicircle, close to the bluff's edge. While this was going on, a shot rang out, and then another, showing that one of the outposts had been fired upon.