The seasoned soldier could have told some things; he could have distinguished calibre from calibre as readily as the skillful fox hunter knows the position of his racing hounds by the quality of their voices. He could have spotted the vindictive crash of "75's," the deep-toned bellowing of "heavies," or, nearer by--had they been in action--the banging of trench mortars. In the sky he could have told from white or greenish-orange flashes, from lace-like wreaths or fixed-star blasts, where shrapnel or high explosive shells had burst; from the ringing of a gas gong he could tell where "green cross" shells were falling; he could, and gladly would, have explained--to his own satisfaction, at least--the many freak phenomena: a solitary light spirally ascending upward until lost in the clouds; sprays of fire and spark-showers illumining the sky; rainbow arcs of angry red that flickered, as an aurora borealis, from horizon to horizon. But the uninitiated Medical Corps unit, numbed to inertia, was only sensible to an overhead riot of screeching demons, as shells hurtling forward were passed and answered by shells hurtling back--a sky of flying steel and a horizon of blasted earth! In moments of greatest concussion, simultaneous with the most blinding flashes, the air about their faces seemed to jump; crazy little vortexes scurried past the dug-out opening, or flew in across the floor, like phantom kittens seized by some curious madness. To Jeb's highly imaginative, and now half-crazed, mind these represented newly liberated souls, in anguish seeking refuge from the hurricane of death and its drenching rain of fire. He had not then found out how many hundreds of shells must be fired to wound one man! On the Allied side the bombardment, with growing intensity, became a _barrage_. Explosions came as thick as drum taps when a roll is sounded. There seemed to be no intermission, really; no more, at any rate, than one's ear can detect between clicks in a telegraph room when the instruments work rapidly. Barrow and Bonsecours ran in. They looked weirdly grotesque in the fitful playing of lights, and Bonsecours shouted something, although no voice seemed to issue from his lips. Then with vigorous gestures he beckoned the men up to him--having come especially to get this new unit straightened out, since his own veterans knew exactly what to do. Jeb had not moved, for the blanket still hung from his shoulders. Neither had the others arisen from their bunks, so bewildered were they also by the chorus of death engines. "Up now, and active!" the great surgeon yelled. "Stretchers! You go out shortly!" "Go out!" Jeb screamed, finding his voice in a burst. "Go out!" he screamed again. "God Almighty, no one can go out _there_!" His face was ghostlike, his eyes were large, staring, vacant. Bonsecours stepped nearer and studied him, bellowing in a tone that had made more than one man obey: