Night comes suddenly in that part of the Southwest. One minute it is daylight, and almost the next the stars are out and the coyotes yelping.
As night advanced a deep quiet fell over the captives and their captors. The horse and burro could be heard tramping around the spring, but these sounds, and the occasional bark of a coyote, were all that broke the stillness.
Bisbee, sitting by the entrance into the notch, was as upright and silent as a black statue. Jacks, with a blanket under him, was lying across the entrance and snoring. Midnight was passed and the hour had come for Matt to make his attempt, so he reached over and touched his chum on the shoulder.
"I'm off, old chap!" he whispered, his lips close to Chub's ear. "I've tied my shoes together by the laces and they're hanging around my neck—I can climb better and make less noise in my stocking-feet."
Chub reached out his hand and wrung Matt's fervently.
"I think it's foolish for you to try to get that notice to Phœnix, old chum," he answered, "but I appreciate what you're tryin' to do for the McReadys, just the same. If ever a fellow was true to his friends, it's a cinch that it's Motor Matt."
"I hate to pull out and leave you, Chub," went on Matt, "but there's only one motor-cycle, you know, and, besides, you can't leave here until you find out about your father."
"That's all to the good. We've got to separate. Good-by and good luck."
"Be ready to run when you hear me yell," finished Matt. "So-long, Chub."
It was as dark as a pocket in the notch, and Chub could not see Matt as he moved noiselessly across to the other wall. Presently, by straining his ears, Chub could hear muffled sounds—a sifting downward of sand, the faint crunch of a loose stone under a stockinged foot, a stifled breathing, as of some one working hard and trying to work quietly. Steadily the sounds mounted up and up. Chub, holding his breath, fixed his eyes on the blank darkness and waited. He almost fell off his boulder when he saw the blurred form of Bisbee lean forward, and heard him call: