o 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 tail-board 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 Canyon 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."

"Tell you it wuz, Mr. Gordon," Jim insisted. "I done seen his
face clar in de light, and he done go into Mr. Cullen's car whar
de old gentleman wuz sittin'."

That set me whistling to myself, and I laughed to think how near
I had come to giving nitroglycerin to a fellow who was only
shamming heart-failure; for that it w