All agreed that this did seem about the only thing to do under the circumstances, and accordingly Tom handed the wheel over to the sailor while he went below to “stand by” the engines. In that muddy stream, with its sand banks and shoals, the maneuver they were going to try would call for some delicate seamanship and swift handling of the motor. Captain Andrews, with his lips grimly compressed, grasped the wheel and sounded a signal. Slowly the _Vagrant_, which had been “hanging” motionless, began to drop back with the current. “Too bad we can’t turn around,” complained Jack. “Wouldn’t dare to chance it,” rejoined the captain, “for all we know there may be a sandbank on either side of us right now.” A deathlike silence hung over the _Vagrant_ as she drifted stern first down the river. The wheel spun swiftly this way and that under the helmsman’s muscular direction. “She goes as well backward as she does forward,” Ned was beginning, when there came a sudden shock that almost threw them off their feet. Jupe, in fact, did fall sprawling on the bridge. At almost precisely the same instant a shower of bullets whizzed above them, singing a sinister song as they screeched about the motor craft. Dense brush lined the banks, and the shooters were well concealed in it. Not even a puff of smoke betrayed their exact whereabouts. And, while this hailstorm of lead whistled about the adventurers, they realized all too clearly that the _Vagrant_ had run hard and fast on one of the very sandbanks the captain had dreaded. One thing, however, speedily became evident, and that was that the bullets had not harmed them, because they were not intended to—yet. The shower of lead was aimed high above their heads. Presently it ceased altogether. “That was a warning,” decided Captain Andrews. “Boys, your folks are certainly surrounded by a barb-wire fence.” The lads did not answer. But as they sensed the nature of the obstacles that were piling up in the way of their enterprise, a look of consternation came over their faces. “The Chadwick Relief Expedition,” as they had christened it, appeared to have run up against a stone wall. “I guess we are not in any danger of another fusillade if we stay where we are, or keep on dropping back,” said Captain Andrews after an interval of thought, “but if we try to keep on going we’ve had a sample of what to expect.” The boys could not but agree with him. At length Jack spoke. “Hadn’t we better try to get the _Vagrant_ off whatever we’ve struck?” he said. “I’ve got a plan in my head in that case; but I don’t think this is the healthiest place to discuss it.” “We can put out a light anchor and try to warp off,” said Captain Andrews.