"I feel sure that there's a real battle going on," said Frank. "The firing is too heavy and too continuous for a rear guard action. But as to who is winning, we can't tell. Sometimes the firing seems to be a little nearer again, but that might be because of the wind. And as for the trains that are going through, that doesn't really mean anything. They might have decided to send troops to the front by another railway. They control the line through Rheims, too."

But the morning after they had decided that there was no real way to tell what was happening, something definite did come up. Nearly all the troops in Amiens moved south. Only a few hundred remained, enough to garrison the town and control the railway, since there seemed no danger of an allied raid. But the fact that the other troops were being sent up to the front indicated that the fighting was assuming a character far more desperate than the Germans had expected.

"They must be fighting on the line of the river Marne," said Frank. "You see, during that long retreat, there was time to entrench there. And open field entrenchments seem to be better than fortified places. Look at how quickly Namur fell, when everyone thought it would hold the Germans back for days."

"The country there is difficult, too," said Henri. "My father said once that it was there that the garrison of Paris should have fought first in 1870, instead of waiting inside the forts for the Prussians to come."

"I think that everything favors us now, for the first time," said Frank. "The Germans have been winning—they have made a wonderful dash through Belgium and France. They must have got very close to Paris. I believe the roar of guns is as easy to hear in Paris as here. And then, suddenly, when they think they are to have it all their own way, their enemy turns and faces them, and holds them. That much we may be sure of. The battle has been raging now for four days at least, perhaps for five. And the firing has certainly not gone further away. Even if we are not gaining, it is a gain if the Germans cannot advance."

They were glad now that they were busy. A few refugees from the south were coming, driven back by the Germans. Perhaps they would rather have tried to reach Paris, but the battle stopped that. And always there were errands to be run, and messages to be carried. It went against the grain to obey the orders of German officers, and to be obliged to salute these officers whenever they were encountered, but it was necessary. And the scouts of Amiens, when they knew what their duty was, did it, no matter how unpleasant it might be.

Now the troops who formed the garrison of Amiens changed almost daily. Older men were now in the tents, and some young boys.

"The last classes of their reserves must have been called out," said Frank. "These are not first line troops that are up, but the ones who are supposed to guard lines of communication and to garrison interior fortresses."

There were times when more officers than men seemed to be in the town. Amiens seemed to be used as a point where shipments of supplies and of ammunition for troops at the front were concentrated and diverted to the various divisions at the front. This involved the presence of a great number of officers of the commissariat department, who seemed to work night and day.

Men fight best on a full stomach, and the Germans understood this thoroughly, and saw to it that their soldiers did not have to go into battle hungry. Amiens also formed the headquarters of one branch of the German flying corps. Here aviators in great numbers were present constantly. Damaged monoplanes and biplanes were brought back for repairs. And it was this fact that brought a startling experience to the two scouts. For one day, as they rode on their bicycles on an errand through the square before the Hotel de Ville, they were arrested by a sudden fierce shout. An officer ran out toward them, his face distorted with anger. And Frank, with a sinking heart, recognized him as the man who had fired at Henri on the night they had burned the Zeppelins.