His eyes strayed through the open door at his back. Through it he caught the square of light from the north window. A semi-circle of shadow above its sill he knew to be Spider's head. Spider was watching there alone. His post was an important one. That window looked out upon a small barn and the towering cottonwood tree. The tree was fully six feet through. The Captain had told of swinging from its branches as a child. "It's strange," Johnny whispered to the girl, "sitting here in this quiet little gray house where men and women have lived their lives away without a breath to disturb their calm, waiting for an attack. It--why, it's like the silence that must have hung over the fields of poppies in France during the Great War." "Do you think they'll truly come?" Alice whispered back. "Or was it just a scare? They may be in Chicago, you know. The Whisperer is." "They are not a mile away. They will come. Drew believes they'll come, and Drew seldom makes a mistake." "Promise me--" She pressed his arm. "If I go to--to--to the Last Round-Up and you--you are spared, you'll look after the boys and--and help Gluck to be a good brave cop when he grows up." There was a little tremor in her voice. "I promise!" Johnny whispered huskily. A moment later Johnny's eyes swept the wide white field before him, then the narrow road that lay beyond. For a space of seconds his eyes remained fixed upon a dark spot on that road. "Does it move?" he asked himself. In the end he decided that it did not. Breathing more easily, he turned to look through the door at his back, into the room beyond. He started and stared. Something was missing. The dark semi-circle that had been Spider's head was gone. "That's queer!" he muttered low. To Alice he whispered: "Keep a sharp watch. I'll be back." Next instant he was gliding noiselessly across the floor. Ten seconds and he was staring at a vacant spot where the other boy had been. "Spider!" He all but said the name aloud. "Spider! He is gone!" Instinctively his hand sought the latch to the door close beside that north window. It gave to his hand. "It--it's not locked," he whispered. "But it _was_ locked. I locked it myself." Spider was gone, sure enough, not alone from his post, but out of the building. At once his head was in a whirl. What was he to make of it? Was Spider yellow, after all? Had he decided to make a break all by himself? With his uncanny power of climbing, of getting through places unobserved, he would almost surely escape. "And yet--" he whispered, "is that like Spider?" He could not feel that it was. He recalled times when the boy had appeared utterly fearless, absolutely loyal. "And yet, he was only a boy from the city streets. Supposing--" Doubt assailed him. Supposing Spider had only pretended to be loyal. Supposing that during all this time he had been in league with Iggy the Snake and his gang? Supposing it had been he who had tipped off the gang to their plans for a Christmas party!