Two hundred yards west of their refuge were the American lines. Sprinters such as Hal and Chester could easily have covered the distance in half a minute; and it was not for want of courage that so far they had failed to make the effort. It was plain common sense that kept them in their present position. On all sides of them--between the American lines and the most advanced German positions less than two hundred yards from the spot where the opening of this story finds the two boys--the ground was dotted with shell holes similar to the ones in which Hal and Chester found themselves. Less than fifty yards due north of Hal and Chester was a second inhabited shell hole. From this four German infantrymen had amused themselves during the day by taking occasional shots at the two lads when either exposed himself over the top of their refuge. This was the reason that Hal and Chester, once in the comparative safety of the shell hole, had elected to remain there rather than to risk a dash toward the American lines. The same reasoning kept the Germans in their refuge. They were not willing to risk a shot from their adversaries by a dash toward the German positions. It was the twentieth day of March, 1918. Although neither Hal nor Chester knew it then, it was the eve of what was to prove Germany's second grand attempt to sweep back the Allied and American troops and march triumphantly into Paris. A warm afternoon sun shone down into the shell hole where Hal and Chester were awaiting the coming of darkness, when, they had decided, they would make an effort to reach their own lines. "Guess the Boches are not enjoying themselves any better than we are," Hal said, as he pulled his cap farther down over his eyes. "I imagine they're fretting a bit worse," agreed Chester. "You know the Hun doesn't bear up very well under adversity." "Adversity?" grinned Hal. "It's the sun they are trying to bear up under now." "Well, whatever it is," declared Chester, somewhat nettled, "I don't believe they like it very well." "I don't like it either, but what am I going to do about it?" Hal wanted to know. "You might try a little sprint," Chester suggested. "Not much. I feel reasonably secure here and I think I'll stick awhile. The thing that mystifies me, though, is why the Germans haven't sent relief to our friends in the next hole." "On the same reasoning," said Chester, "why hasn't Captain O'Neil made an effort to reach us?" Hal shrugged his shoulders. "Guess he is playing for the safety of the greatest number," was his reply. "If he tried to rescue us the Germans also would probably advance and that would mean a battle. My idea is that Captain O'Neil has been ordered to avoid that right now!" "All the same," said Chester, "they are bound to know we're here, and it seems to me they could do something for us."