"Yes. If they flew over Belgium they would have to cross some territory that the Germans do not hold, and word would go to Antwerp and from there to the army here. Now quickly! They will be here soon. They are coming nearer every minute."

They went to the barrels as fast as they dared. There was nearly a score of them, all close together. Each had a tap, and it was proof enough that they contained petrol to open the tap of one. The smell identified them beyond any doubt whatever.

"Come on, and help me dig a hole," said Frank. He dropped to his knees, and began scooping out the soft earth with his hands. Henri fell to with a will, though he was sadly puzzled. But when the hole had been dug to a depth of perhaps two feet, and Frank began to hollow out a trench toward the barrels he began to understand. And as soon as he did, he worked as hard as Frank himself, careless of torn finger nails and bleeding hands. They carried the trench to the foot of one of the barrels, and Frank turned the tap. The gasoline ran out into the trench, and flowed to the hole. Frank ran back to the hole.

"Stop it when I give the word," he said. "Now!"

Then he was busy with the copper wire he had brought from the automobile for several minutes. The wire had been carried either to repair cut telegraph or telephone wires, or to serve as the conductor for a field system of lighting. But whatever its original purpose had been, Frank was thankful now that he had found it. He worked fast, and was satisfied at last.

"Now a little straw and a few twigs over the hole and the trench—and the sooner they come, the better!"

"Yes, the sooner, the better!" echoed Henri, tremendously excited, now that he understood, even if rather vaguely, what Frank planned. "Vive la France! A bas les Allemands!"

As they went back toward the road Frank trailed the wire behind him in two lengths. And when they reached the road, he dropped into the ditch, and was busy for some minutes.

"Now if it only works!" he said. "Perhaps it will; perhaps it won't. But it can't do any harm. That's certain."

"They're coming closer. I think I can see their shapes now—and there are two of them," said Henri. "Do you see?"