"Maybe he has his suspicions that we're going to give him a little surprise party," remarked Billy, "and that's his way of telling us that he's ready to welcome us with open arms." "Fix bayonets!" came the command from the officer in charge, and there was a faint clink as the order was obeyed. "It won't be long now," murmured Tom. "But why don't the guns open up?" "They always do before it's time to charge," commented Billy, as he shifted his position a little. "I suppose they will now almost any minute." "I don't think there'll be any gun fire this time before we go over the top," ventured Frank. "What do you mean?" asked Bart in surprise, as he turned his head toward his chum. "Do you know anything?" queried Tom. "Not exactly know, but I've heard enough to make a guess," replied Frank. "I think we're going to play the game a little differently this time. Unless I'm mistaken, the Huns are going to get the surprise of their lives." "Put on gas masks!" came another order, and in the six seconds allowed for this operation the masks were donned, making the men in the long line look like so many goblins. It was light enough for them to see each other now, for the gray fingers of the dawn were already drawing the curtain of darkness aside from the eastern sky. One minute more passed--a minute of tense, fierce expectation, while the boys gripped their rifles until it seemed that their fingers would bury themselves in the stocks. Crash! With a roar louder than a thousand guns the earth under the German first-line trenches split asunder, and tons of rock and mud and guns and men were hurled toward the sky. The din was terrific, the sight appalling, and the shock for an instant was almost as great to the Americans as to their opponents, though far less tragic. "Now, men," shouted their lieutenant, "over with you!" and with a wild yell of exultation the boys clambered over the edge of the trench and started toward the German lines. "We're off!" panted Frank, as, with eyes blazing and bayonet ready for instant use, he rushed forward in the front rank. "To a flying start!" gasped Bart, and then because breath was precious they said no more, but raced on like greyhounds freed from the leash. On, on they went, with the wind whipping their faces! On, still on, to the red ruin wrought by the explosion of the mine. For the first fifty yards the going was easy except for the craters and shell holes into which some of the boys slid and tumbled. The enemy had been so numbed and paralyzed by the overwhelming explosion that they seemed to be unable to make any resistance. But the officers knew, and the men as well, that this was only the lull before the storm. Their enemy was desperate and resourceful, and though the cleverness of the American engineers had carried through the mine operation without detection, it was certain that the foe would rally. Fifty yards from the first-line trench--forty--thirty--and then the German guns spoke.