To the west, seemingly quite near, a flash of flame gleamed against the sky, then another and another and another, and in a moment a savage rumble as of distant thunder drifted to their ears. "What is it?" asked Stewart, staring at the ever-increasing bursts of flame. "Not a battle, surely!" "It is the forts at Liège!" cried the girl, hoarsely. "The Germans are attacking them, and they resist! Oh, brave little Belgium!" The firing grew more furious, and then a battery of searchlights began to play over the hillside before the nearest fort, and they could dimly see its outline on the hilltop--strangely like a dreadnaught, with its wireless mast and its armored turrets vomiting flame. Above it, from time to time, a shell from the German batteries burst like a greenish-white rocket, but it was evident that the assailants had not yet got their guns up in any number. Then, suddenly, amid the thunder of the cannon, there surged a vicious undercurrent of sound which Stewart knew must be the reports of machine-guns, or perhaps of rifles; and all along the slope below the fort innumerable little flashes stabbed upward toward the summit. Surely infantry would never attack such a position, Stewart told himself; and then he held his breath, for, full in the glare of the searchlights, he could see what seemed to be a tidal wave sweeping up the hill. A very fury of firing came from the fort, yet still the wave swept on. As it neared the fort, what seemed to be another wave swept down to meet it. The firing slackened, almost stopped, and Stewart, his blood pounding in his temples, knew that the struggle was hand to hand, breast to breast. It lasted but a minute; then the attacking tide flowed back down the hill, and again the machine-guns of the fort took up that deadly chorus. "They have been driven back!" gasped the girl. "Thank God! the Germans have been driven back!" How many, Stewart wondered, were lying out there dead on the hillside? How many homes had been rendered fatherless in those few desperate moments? And this was but the first of a thousand such charges--the first of a thousand such moments! There, before his eyes, men had killed each other--for what? The men in the forts were defending their Fatherland from invasion--they were fighting for liberty and independence. That was understandable--it was even admirable. But those others--the men in the spiked helmets--what were they fighting for? To destroy liberty? To wrest independence from a proud little people? Surely no man of honor would fight for that! No, it must be for something else--for some ideal--for some ardent sense of duty, strangely twisted, perhaps, but none the less fierce and urgent! Again the big guns in the armored turrets were bellowing forth their wrath; and then the searchlights stabbed suddenly up into the sky, sweeping this way and that. "They fear an airship attack!" breathed the girl, and she and Stewart stood staring up into the night.