There were hoa.r.s.e commands to halt, and another volley followed the first. At the same time a number of dark figures threw themselves in the road, shouting and waving their hands.

Frank leaned forward, threw on all speed, and the machine responded with a leap that almost unseated the riders. The crowd in front scattered as the machine rushed at them, but one of them was not quick enough and was hurled twenty feet away.

More shots followed the daring riders, but they were now beyond range.

For another mile they kept up the killing pace and then Frank slowed up a little.

"Ran right into their arms that time," he e.j.a.c.u.l.a.t.ed.

"We were mighty lucky to come through with a whole skin," replied Bart.

"More than the machine has done, I'm afraid," remarked Frank. "I can tell by the way she runs that there's something wrong with the tires."

He looked behind, and seeing no signs of pursuit, he stopped the motorcycle and dismounted.

Something had indeed happened to the tires. Both the front and rear ones had been punctured by bullets. The air had gone out of them.

"Hard luck," exclaimed Bart.

"Never mind," returned Frank. "We'll ride her flat as long as we can and if worse comes to worse we'll ride her on the rims. We've got to get that message to the general no matter what happens."

"We'll get it there if we have to travel on our hands and knees,"

affirmed Bart.

"It won't come to that, I hope," laughed his companion, as he bound the flat tires fast with straps. Then he settled himself again in his seat and started the machine.

It went along more slowly now, and their troubles were increased by the fact that their route had carried them into a main road that was filled with motor lorries--huge trucks loaded with men and supplies that rushed on with the speed almost of an express train.

The lorries had the right of way, and individual riders had to look out for themselves. Sometimes they came down two abreast, filling the whole width of the road, and in such cases the boys had to dismount and draw to the side of the road until they had pa.s.sed. If their machine had been in condition, they might have kept ahead by sheer speed, but in its present crippled state they would have been run down. And to be run down by one of those Juggernauts would have meant instant death.

On one such occasion they were hugging the fence, with their machine standing between them and the road. A lorry came thundering by, but just as it was nearly opposite, it swerved and struck the machine. It was torn from Frank's hand and hurled in front of the lorry which ran over and completely wrecked it.

The lorry tore on, leaving the two chums looking at each other in consternation.

"That's worse by long odds than the German bullets," exclaimed Frank.

"I guess we'll have to do the hands and knees stunt you were talking about a little while ago."

"We must be pretty near to the English general's headquarters now anyway, aren't we?" asked Bart.

Frank consulted his route by the aid of a flashlight that he carried with him.

"About two miles," he announced. "Put on some speed now, Bart. We'll run most of the way and jog-trot the rest."

They let no gra.s.s grow under their feet, and fifteen minutes later they had reached the general's headquarters and were ushered into his presence. He seemed to be greatly agitated and was talking with great emphasis to a group of officers who surrounded him.

He took the papers that the boys had brought and read them over hurriedly.

"Very good," he announced briefly. "There is no answer. Were your orders to go back to your regiment to-night?"

"No, sir," replied Frank.

"In that case my orderly will find quarters for you," replied the general, and he gave directions to an officer who took them in charge and saw them safely bestowed for the night.

"That was some wild ride?" grinned Frank, as they were getting ready for sleep.

"It sure was," laughed Bart, "especially that part where the German bullets were zipping all around us. Wait till we tell Billy about it.

He'll be green with envy."

"Well, we carried out our orders anyway," said Frank. "I'm glad that we'll be able to tell the captain so tomorrow morning."

But they did not report to their captain the next morning, nor for several following mornings, for when they woke they found that a condition had developed that was full of peril to the Allied cause.

The German plan had been to strike at the junction point of the Allied armies. If they could separate them there would be a chance to turn upon one of them and crush it with overwhelming forces and then at their leisure destroy the other.

In this they had come very near succeeding. A threatening gap had developed between two of the most important armies that were holding that portion of the front. The armies had lost touch with each other and the gap had gradually widened until at one place the armies were eight miles apart.

The only helpful thing about the situation was that the Germans themselves did not know of the gap until it was too late to take advantage of it. The very speed with which they had pushed forward had thrown their forces into confusion. Brigades and regiments had become badly mixed and it took some time to straighten matters out.

But if the Germans did not know how matters stood, the Allied commanders knew it only too well. It was this that explained the agitation that the boys had noticed in the general the night before.

He had been called upon to close the gap. Upon his shoulders rested for the time the salvation of the Allied cause.

If he had had sufficient forces at his command, the problem would have been comparatively simple, provided he had been given time to solve it.

But he had neither time nor men. He had only fifty cavalrymen. He lacked guns and ammunition. The hard-pressed armies at the right and left were battling desperately against the on-rushing German hordes and could spare him little.

"Looks as if he had to make bricks without straw," said Frank to Bart the next morning, when the state of things had been explained by the orderly who had taken them in charge.

"It's a case of must," said Bart, "and from the squint I had at the general last night he's the one who can do the job if it can be done at all."

"Will you stay and help?" asked the orderly. "Every man will help.

The general's picked up three hundred American engineers working on a road nearby. Every one of them has thrown down his pick and shouldered a rifle."

"Bully for the engineers!" cried Frank.

"Will you stay?" asked the orderly. "Of course you can return to your own command if you want to."

"Will we stay?" exclaimed Frank. "Give me a gun. I know my captain would be willing."

"You can't drive us away," Bart almost shouted.

It was a scratch army that the general finally got together. Some of his men had never handled a gun before. Some were drivers, some were telegraph linemen, some were cooks. But he made the most of what he had. He himself was here, there and everywhere, having trees felled to obstruct the roads, planting machine guns in strategic places, digging shallow trenches, resting neither by day or night.

Frank and Bart worked like beavers. They were placed in charge of machine-gun crews, and their deadly weapons kept spitting fire until they were almost too hot to handle. Again and again they beat back German detachments. They fought like fiends. They never expected to come out of that fight alive. The odds seemed too tremendous.

"It's like Custer's last charge," panted Frank. "There wasn't one of his troopers left alive. But I'll bet that not one of them was sorry he was there."

"I'm glad that motorcycle carried double," replied Bart. "I'd have been cheated out of a lot of lovely fighting if it hadn't."

They fought desperately, savagely, their bodies tired to the breaking point, but their courage never failing. And at last they won out. The armies rejoined each other. The gap was closed. And Frank and Bart rejoiced beyond measure that they had been able to do their part in the closing.