"A new weapon of death," said Fleury. "The fighters move in the air, under the water, on the earth, everywhere."
"The Uhlans are off again," said John. "Whatever their duty was the steel arrows have sent them on it in a hurry."
"And we're about to move too. See, these batteries are limbering up preparatory to a withdrawal."
Inside of fifteen minutes they were again marching eastward, though slowly and with the roar of battle going on as fiercely behind them as ever. John heard again from some of the talk of the guards that the Germans had five armies along their whole line, but whether the one with which he was now a prisoner was falling back with its whole force he had no way of knowing. Both he and Fleury were sure the prisoners themselves would soon cross the Marne, and that large detachments of the enemy would go with them.
Thoughts of escape returned. Crossing a river in battle was a perilous operation, entailing much confusion, and the chance might come at the Marne. They could see too that the Germans were now being pressed harder. The French shells were coming faster and with more deadly precision. Now and then they exploded among the masses of German infantry, and once or twice they struck close to the captives.
"It would be a pity to be killed by our own people," said Fleury.
"And at such a time as this," said John. "Do you know, Fleury, that my greatest fear about getting killed is that then I wouldn't know how this war is going to end?"
"I feel that way myself sometimes. Look, there's the Marne! See its waters shining! It's the mark of the first great stage in the German retreat."
"I wonder how we're going to cross. I suppose the bridges will be crowded with artillery and men. It might pay the Germans just to let us go."
"They won't do that. There's nothing in their rules about liberating prisoners, and they wouldn't hear of such a thing, anyhow, trouble or no trouble."