I glanced down, and sure enough, there were six empty cartridge-shells. I stood looking blankly at them, hardly able to believe what I saw; for Albert Cullen had said distinctly that the train-robbers had fired only four times, and that the last three Winchester shots I had heard had been fired by himself. Then, without speaking, I walked slowly back, searching along the edge of the road-bed for more shells; but, though I went beyond the point where the last car had stood, not one did I find. Any man who has fired a Winchester knows that it drops its empty shell in loading, and I could therefore draw only one conclusion—namely, that all seven discharges of the Winchesters had occurred up by the mail-car. I had heard of men supposing they had fired their guns through hearing another go off; but with a repeating rifle one has to fire before one can reload. The fact was evident that Albert Cullen either had fired his Winchester up by the mail-car, or else had not fired it at all. In either case he had lied, and Lord Ralles and Captain Ackland had backed him up in it.
CHAPTER V
A TRIP TO THE GRAND CAÑON
I stood pondering, for no explanation that would fit the facts seemed possible. I should have considered the young fellow's story only an attempt to gain a little reputation for pluck, if in any way I could have accounted for the appearance and disappearance of the robbers. Yet to suppose—which seemed the only other horn to the dilemma—that the son and guests of the vice-president of the Missouri Western, and one of our own directors, would be concerned in train-robbery was to believe something equally improbable. Indeed, I should have put the whole thing down as a practical joke of Mr. Cullen's party, if it had not been for the loss of the registered letters.
Even a practical joker would hardly care to go to the length of cutting open government mail-pouches; for Uncle Sam doesn't approve of such conduct.
Whatever the explanation, I had enough facts to prevent me from wasting more time on that alkali plain. Getting the men and horses back onto the cars, I jumped up on the tailboard and ordered the runner to pull out for Flagstaff. It was a run of seven hours, getting us in a little after eight, and in those hours I had done a lot of thinking which had all come to one result—that Mr. Cullen's party was concerned in the hold-up.
The two private cars were on a siding, but the Cullens had left for the Grand Cañon the moment they had arrived, and were about reaching there by this time. I went to 218 and questioned the cook and waiter, but they had either seen nothing or else had been primed, for not a fact did I get from them. Going to my own car, I ordered a quick supper, and while I was eating it I questioned my boy. He told me that he had heard the shots, and had bolted the front door of my car, as I had ordered when I went out; that as he turned to go to a safer place, he had seen a man, revolver in hand, climb over the off-side gate of Mr. Cullen's car, and for a moment he had supposed it a road agent, till he saw that it was Albert Cullen.
"That was just after I had got off?" I asked.
"Yis, sah.
"Then it couldn't have been Mr. Cullen, Jim," I declared, "for I found him up at the other end of the car."