The two men were gone a long time; disappointed in the express, they had searched the registered mail.
As I stood there on the track before the engine I had a strange sensation. It was very still; there was a ghostly fog, and somewhere beyond me, as though out of the sky, I heard whispering voices.
I strained my ears to listen, standing as one does on tiptoe.
But I could not be certain. No word was audible to me nor any decided voice, but now and then there seemed to be a murmuring in the fog, and, what was beyond understanding, it seemed behind the engine in the clouded sky.
What human creatures could thus whisper in the sky?
Mooney and White returned presently in no very pleasant mood. I think the time taken with the thing made them uneasy. White had the loot sack and we started along across the field, to where we had left the automobile on the road.
It was then that I got the explanation of the mysterious voices.
There were three hobos riding on the top of the mail car. They had been witnesses of everything that had occurred. They sat there like immense buzzards outlined against the dim light of the sky. Mooney stopped a moment. He seemed to reflect, turning his weapon about in his hand. Then he spoke to the derelicts on the top of the car.
“If they pinch you for this job,” he said, “write me a letter.”
And he went on.