Harrison fired at the sound, and a sharp, lurid flash replied to his own. He staggered back as he fired again, and an answering flash doubled him up. Gamely he pulled the trigger again and two spurts of flame, so close to each other that they seemed almost to merge, sent him staggering and reeling toward the edge of the canyon. Tripping over an inequality in the earth he threw out his arms, fought to regain his balance and with a sob plunged over the wall into the darkness below. Down on the trail Gates muttered in sudden horror as he felt the wind of the hurtling body, and he leaned against the wall, white, sick, shaken. A muffled, sickening sound came up from the pit, and Gates dropped to his hands and knees, not daring to stand erect. "Nat!" he cried. "_Nat!_ Was that you? _Nat! Nat!_" At the top of the trail a rapier-like flash of fire split the darkness, and then a series of lurid spurts of flame stabbed in short jets, rapidly, regular as the ticking of a clock, marking the place where two heavy guns crashed and jumped as they poured forth a stream of lead down the narrow rock shelf that formed the precarious trail. The canyon roared in one prolonged reverberation and the bullets whined and spatted and screamed in high falsetto as they cleared the wall or struck it to glance out into the valley below. Gates, on his hands and knees, shaken, sick with horror, crept slowly downward, oblivious to the crashing, rolling thunder and the flying lead. "I didn't mean it, Nat!" he muttered over and over again. "I didn't mean it; not a word of it!" A sharp _spang!_ sounded on a rock close to his head and a hot splinter of lead cut through his cheek. He stopped and spat it out, his nerve returning as a cold rage swept over and steadied him. Jerking his gun loose he emptied it up the trail, and, methodically reloading, emptied it again, slowly, deliberately, moving it a little at each shot so as to cover a short arc. Another spurt stabbed the darkness above, and his gun, again refilled, replied to it. Again the canyon sent roaring echoes crashing from wall to wall as flash answered flash. Then suddenly the gun below grew silent, and the guns above spat twice spitefully without a reply, and they, too, ceased. Gates stirred and slowly raised himself on an elbow, groping blindly for his gun. His trembling hand struck it blunderingly and knocked it over the edge of the trail as his numbed fingers sought to close over it. Dazed, racked with pain, he sobbed senseless curses as he slowly dragged himself down the trail, desperately anxious to reach his picketed horse before his reeling senses left him.