"A gun? Say, it must have been the grandfather of all the cannon the Huns ever made," declared Jimmy. "Are any of you alive?" "Guess we're all alive," answered Bob, as he slowly arose and shook some of the dust from him. For the dust was thick all over, in clouds and scattered about. Some of it was flour dust and other was the lime and mortar that had held together the front wall which had collapsed and slid outward. The whole front of the mill was open. There was no doubt about their all being alive, but, for a time, even this had been in doubt. They were still stunned, but they managed to gather in a knot about Jimmy. They were hardly able to breathe, partly because of the shock and partly because of the choking dust. "There goes our defense," said Bob, gloomily, pointing to where the machine-gun stood--the one they had decided to use against their enemies. It had been crushed by the falling wall. "Lucky we had the rations in the back room," commented Roger, "Else we'd go hungry." "We may yet," returned Jimmy, grimly. "What do you mean!" asked Bob, anxiously. "Well, I don't believe that was a chance shot," went on the young sergeant. "If they see the mill still standing they may try another, and that may take off the roof. And then----" "Whoa! Hold on a minute! A little at a time!" protested Bob. "This is enough. Don't give us any more." "We've got to know where we're at!" declared Jimmy, and there was a new quality to his voice. "If this mill is within range of the German guns, and, unquestionably, it is, we've got to get out." "Or go down cellar," added Roger. "I don't believe any cellar, unless it was double bomb proof, would be safe if another shell like that came over," said Franz. "Was it a German shell or one of ours?" asked Bob. "That would be interesting to know. I don't suppose, though," he went on, "that it really makes much difference, after you're dead, whether you're killed by an enemy shell, or by one fired in mistake by one of your friends. At the same time if the American guns have come up it may mean that the Germans will have to retreat and we'll be safe." "I wouldn't go so far as to say that," declared Jimmy. "It will mean a big battle, anyhow, if the Americans and some of the French and British have come up. And that may mean we'll have a chance to join our friends. But, in the meantime, maybe we can tell whether that was a Hun shell, sent to blow this mill off the earth, or whether it was from the good old United States." Cautiously they advanced across the floor, toward what had been the front of the mill. Caution was necessary, for with the collapse of the front wall and part of the sides, the floor supports were weakened. "No telling where that shell landed," declared Bob. "It's buried deep, and about ten tons of mortar and bricks are on top of it. If we had seen it coming----"