s movements from across the river. How much they might
already suspicion his discoveries he possessed no means of knowing, yet,
conscious of their own guilt, they might easily feel safer if he were
also put out of the way. He had no anticipation of open attack, but must
guard against treachery. As he rode, his eyes never left those far-away
sand dunes, although he perceived no movement, no black dot even which
he could conceive to be a possible enemy. Now that he possessed ample
time for thought, the situation became more puzzling. This tragedy which
he had accidentally stumbled upon must have had a cause other than blind
chance. It was the culmination of a plot, with some reason behind more
important than ordinary robbery. Apparently the wagons contained nothing
of value, merely the clothing, provisions, and ordinary utensils of an
emigrant party. Nor had the victims' pockets been carefully searched.
Only the mules had been taken by the raiders, and they would be small
booty for such a crime.

The trail, continually skirting the high bluff and bearing farther
away from the river, turned sharply into a narrow ravine. There was a
considerable break in the rocky barrier here, leading back for perhaps a
hundred yards, and the plainsman turned his horse that way, dismounting
when out of sight among the bowlders. He could rest here until night
with little danger of discovery. He lay down on the rocks, pillowing
his head on the saddle, but his brain was too active to permit sleeping.
Finally he drew the letters from out his pocket, and began examining
them. They yielded very little information, those taken from the older
man having no envelopes to show to whom they had been addressed. The
single document found in the pocket of the other was a memorandum of
account at the Pioneer Store at Topeka, charged to John Sibley, and
marked paid. This then must have been the younger man's name, as the
letters to the other began occasionally "Dear Will." They were missives
such as a wife might write to a husband long absent, yet upon a mission
of deep interest to both. Keith could not fully determine what this
mission might be, as the persons evidently understood each other so
thoroughly that mere allusion took the place of detail. Twice the name
Phyllis was mentioned, and once a "Fred" was also referred to, but in
neither instance clearly enough to reveal the relationship, although the
latter appeared to be pleaded for. Certain reference