"It will cost him a terrible toll to come through here," declared Chester grimly. "Of course. But if he really means to break through, and the movement is not a feint to cover an advance elsewhere, he won't worry about the sacrifice in human lives. He will attempt to break through, cost what it may. If successful, he'll probably swing south toward Paris." "Well, he won't get there." "I don't think he will, either. But all those possibilities must be taken into consideration." "We don't have to worry about them," said Chester. "I guess Marshal Foch and his staff haven't overlooked any such possibilities. All we've got to do is what we're told." "Right you are, Chester. Nevertheless, we're free to speculate if we feel so disposed." As Hal had predicted, the German attack came soon. Under cover of the semi-darkness of early morning, the gray-clad hosts advanced to the attack. For miles along the long battle line, Germans streamed from their trenches and marched slowly toward the Allied positions only a few hundred yards away. The enemy came on calmly and with no appearance of haste. Machine guns from British, French and American positions poured a hail of bullets into the advancing ranks; but the gaps made by this fire were immediately filled and the Germans still moved forward, firing with monotonous regularity as they did so. Now they reached the first-line American trenches and poured in. Desperately the Yankee troops fought to drive them out. But, outnumbered as they were by the enemy, they eventually were forced to retire. This retirement was ordered primarily so that the Americans might be kept in contact with the French, to the north, who were forced to give ground under the impetuous advance of the foe. All day the battle raged, first at close quarters, and when the Allies retired farther, the big German guns resumed the bombardment. At nightfall of the second day it became clear to every man in the battle that the German objective, primarily at least, was Ypres, one of the most important towns at the front still in possession of the Allies. Still the Allies gave ground as the enemy advanced. So, at the close of the fourth day of fighting, the Germans had gained miles of territory and seemed in imminent danger of encircling the city of Ypres. But the German advance had been made at terrible cost. Thousands upon thousands of German dead strewed the field. In these few days of fighting the German losses had been greater than in any battle of the war. The losses of the Allies were comparatively light. And still Marshal Foch withdrew his troops slowly.