The Mexican kept on the far side of the rack and whipped his knot together hastily; it was not till he sprang back from his work that she saw the snaky length of an eight foot blacksnake uncoil from his hand. He passed the lash slowly through his fingers, while surveying the stallion with great complacence. The ears of Alcatraz flattened back, a sufficient proof that he knew what was coming; he maintained his weary attitude, but it now seemed one of despair. As for Marianne she refused to admit the ugly suspicion which began to occur to her. But Cordova left her only a moment for doubt. The black streak curled around his head, and through the open window she heard the crack of the lash-end. Alcatraz did not stir under the blow. Once more the blacksnake whirled, and Cordova leaned back to give the stroke the full stretch of arm and body; yet Alcatraz did not so much as lift an ear. Only when the lash hung in mid-air did he stir. The rope which tethered him hung slack, and this enabled the stallion to give impetus to his backward leap. All the weight of his body, all the strain of his leg muscles snapped the rope taut. It vibrated to invisibility for an instant, then parted with a sound as loud as the fall of the whip. The straining body of Alcatraz, so released, toppled sidewise. He rolled like a dog in the dust, and when, with the agility of a dog, he gained his feet, Cordova was fleeing towards the hotel with a horror-stricken face. Even then she could not understand his terror--not until she saw that Alcatraz had wheeled and was bolting in hot pursuit. He came like the "devil-horse" that the Mexican called him, with his ears flattened and his mouth gaping; he came with such velocity that Cordova, running as only consummate terror can make a man run, seemed to be racing on a treadmill--literally standing still. The picket fence which set off the back yard of the hotel gave the man an instant of delay--a terribly vital instant, indeed, that seemed to Marianne to contain long, long minutes. But here he was over and running again. In her dread she wondered why he was not shrieking for aid, but the face of Cordova was rigid--a nightmare mask! Twenty steps, now, to the hotel, and surely there was still hope. No, for Alcatraz sailed across the pickets with a bound that cut in two the distance still dividing him from his master. It had all happened, perhaps, within the space of three breaths. Now Marianne leaned out of the window and screamed her warning, for the faded chestnut was on the very heels of the Mexican. He raised his contorted face at her cry, then threw up both his arms to her in a gesture she could never forget. "Shoot!" yelled Cordova. "Amigo, amigo, shoot! Quick--" Then Alcatraz struck him!