Ten minutes of ducking and dodging found him at last in his own tent.

“Can you beat that?” he exclaimed in a whisper as he switched on the light and looked down at his right hand. “Got that money, all of it. Now I’ll have to find that truck farmer and give it back. Gee! I hope I find him. And I hope his five kids are cute.”

He spread the bills out in a neat pile on his knee. Then he made them into a compact roll and thrust them deep into his pocket. But this was not the end of that affair. It was only the beginning.

He snapped off the light. “Can’t be too careful,” he told himself.

For a moment his head was in a whirl. Then of a sudden he leaned forward in the posture of one who listens intently. A faint sound had come to his ears.

“Footsteps,” he whispered. “Measured footsteps as of a sentry on duty. I wonder—”

Now a fresh sound greeted his ears.

The steady drum of a powerful airplane motor, growing louder and ever louder until it filled the very air, passed directly above his head and then thundered on into the distance.

Once it had passed he forgot the plane. He might well have given it much thought, for the driver of that plane and its precious freight were to enter much into his life. It was the night Air Mail from New York. And on this particular night it bore curious and priceless freight.

CHAPTER II
THE MYSTERIOUS SENTRY