"And where does the road to St. Quentin turn off from this one?"

"It is the next turn, to your left," said Frank, truthfully.

"Good! Then I will be going. Go home, kinder. You will get into trouble if you stay hereabout."

He vaulted upon his horse, and the next moment they heard hoofs clattering along the hard road, and, looking after him, could see the sparks as the iron clashed with the flint of the road's surface.

"That was easy!" said Frank, with a gasp of relief.

"He was alone," said Henri.

"Carrying despatches, I expect," said Frank. "He wouldn't tell us where he was going, naturally, but I bet he's looking for those other troops we saw. Dangerous work, too. But I wonder where he came from. If there are more Uhlans in front, we may get into trouble."

"Suppose we hide the bicycles near here and go along through the fields? Don't you think that will be better, Frank?" was Henri's cautious suggestion.

"Yes, I suppose it will, though it will be slower, too."

"Of course. But if we are going to be stopped all the time along this road, we'll really save time in the end by doing it."

So they made a cache, as Frank told Henri it should be called, hiding their wheels so that they would have a chance of recovering them if they came back this way. They marked the spot not only by landmarks, but by the stars, which were beginning to dot the sky now.

"There may be fighting here," said Frank. "And if there is, this place may look very different before we see it again. If there is a battle the trees will go, and the fences, and all the houses for if they are not burned deliberately, the sh.e.l.ls will destroy them."

"Look, Frank, what is that?"

Henri had turned and was pointing now to the north. There a stream of white light shot into the air, then dropped, and left only its reflection. But in a moment others joined it, and the whole sky to the north was brilliantly lighted. It was like a display of Northern Lights, only nearer and even more brilliant.

"Searchlights, of course," said Frank. "They can throw them on the trenches--and they're good to guard against aeroplanes and dirigibles, too. At night, you see, there'd be a chance for aeroplanes to fly very low and do a lot of damage."

"Can't they hear the engines from the ground?"

"Not always. They have m.u.f.flers on a good many aeroplane motors now, so that they don't make any more noise than a quiet automobile."

"I didn't know that. Well, there's one good thing about the searchlights. We know which way to go. Come on."

"All right. The more I think of it, the better it is not to be on the roads. Here in the fields we're a lot less likely to run into stray parties. And I'd just about as soon meet Germans as allies. If they're retreating and having trouble, they might hold us up as long as the Germans would. They wouldn't believe we really had despatches."

For a time they made good, steady progress. The roar of artillery fire in front of them had been resumed, and now it filled the air, proving that they were much closer to the battle. The great waves of sound beat against their ears, making their heads swim at first, but gradually they grew used to it, and could hear other and more trivial sounds--the chirping of night insects and the occasional hooting of owls.

"I don't hear the rifle fire," said Henri, after a time. "Only once in a while, that is. Why is that, I wonder? Are the big guns drowning it?"

"No. Because if that were the reason, we wouldn't hear it at all. I think they don't do that at night. It's just a case of trying to find the places where the enemy's troops are ma.s.sed, and keeping up a steady fire of sh.e.l.ls to drive them out. Maybe the searchlights help. They've been fighting all day, you know, and even soldiers have to have some rest. They have to eat and sleep or they can't keep up the work."

They crossed more than one road, but stuck to the fields, travelling in a straight line as nearly as they could figure their course. When they had decided to join the Boy Scouts, both had studied the stars, since a knowledge of the heavens is one of the most important things about scouting, and they found what they had learned very valuable now. Thus they could keep their bearings, though owing to their desertion of the roads, Henri confessed that he had very little idea of where they were.

"Along the roads one has landmarks," he said. "I have gone all through here, over and over again. My father used to drive this way very often in our automobile."

"Well, we can't go very far wrong," said Frank, cheerfully. "All we've got to do is to follow the old German maxim, 'March on the cannon thunder!' That was their one rule in 1870, you know and a very good rule it proved too."

So they went on. And they still seemed to be a long way from the seat of the heavy artillery firing when a challenge halted them, as they were about to cross a road.

"'Alt! 'Oo goes there?" called a c.o.c.kney voice sharply.

"Friends," cried Frank, instantly.

"'Alt, friends, while I 'as a look at you," said the sentry.

"Call your officer, please. We are carrying despatches," said Frank.

"I'll call 'im, all right. My word! You ain't nothin' but kiddies, you ain't! 'Ere! Corporal of the guard! I sye! Corporal of the guard!"

He raised his voice in the shout, and a minute or so later a corporal appeared.

"Came up to me, sir," said the sentry. "Said as 'ow they wanted me to call the officer of the guard. Carryin' despatches, they sye they is."

"All right," said the corporal, briskly. "Come with me, my lads. Step smartly when you're told or you may be shot," in a genial voice.

They followed him through a field that seemed deserted, then came to a small cl.u.s.ter of tents, where they stopped.

"Wait here," said the corporal. "I'll bring the lieutenant."

They did not have long to wait before a young officer approached them.

"My word!" he said, when he saw how young they were. "What are you youngsters doing here?"

"We're looking for headquarters, sir," said Frank. "We are carrying despatches from Amiens."

"All right! Give them to me, and I'll see that they're forwarded, my lads," said the officer, with a grin.

"We can't do that, sir," said Frank. "Our orders are to carry them to headquarters--and to give the word Mezieres."

"Ah, that's different, now," said the officer. "Corporal, give me two men to take these despatch-bearers through the lines," came the order.

The giving of the word had made a great change in his att.i.tude. It was plain that before that he had not taken them seriously, but had supposed them to be playing some prank. Now, however, he looked at them curiously.

"Boy Scouts?" he suggested.

"Yes, sir," said Frank. "Detailed to special duty, without uniforms."

"I see! Jolly plucky of you, I call it. I say, you're not French, my lad, are you? How did you get here? Well, never mind! Here's your escort. Be off with you, now."

Their troubles were over now. Within five minutes they were at headquarters. There a weary staff officer received them. They saluted.

"Very well," he said. "Give me your despatches."

Each of them produced his handful of marbles from his pocket, and laid them solemnly before the major. He stared, first at the marbles, then at them.

"What sort of a silly prank is this?" he roared. "Do you think we've nothing better to do than to waste time in jokes? If you were men--"