sat in the
saddle scrutinizing a section of buffalo grass that fringed a clump of
willows near the almost dry bed of the river that doubled slightly as it
came from the basin. Something in the appearance of the grass had
attracted his attention--it was matted, as though something had lain or
rolled in it.

He rode closer, cautiously, for the little trees formed a covert behind
which any one of several dangers might lie concealed--and looked down at
the grass. As he examined the place his lips twisted into a grim smile,
and his eyes grew bright with comprehension.

He rode around the clump of trees, making sure it was not occupied; then
he dismounted.

Someone had been concealed in the covert for many days--a man. For he saw
the imprints of heels, and indentations where spurs had gashed the earth.
The marks were all fresh--recently made. While he watched he saw some
blades of the long grass slowly rise--as though, relieved from some
pressure that had been upon them, they were eager to regain an upright
position. He also saw scraps of food--jerked beef and biscuit--scattered
here and there.

He frowned, convinced that for days a man had occupied the covert,
watching the Rancho Seco; convinced also, that the mystery he had sensed
some days ago had been man-made, as he had felt. The man who had been
there had been a sentinel, a spy, sent by Deveny or Haydon to observe his
movements, and to report them, of course, to one or the other of the two
outlaws.

Harlan remounted Purgatory. His caution had not been wasted, and his
vigilance in guarding the ranchhouse must have been irritating to the man
who had been watching.

He urged Purgatory on again--heading him westward, as before. And when he
reached the crest of a slight rise in the valley--from where he could see
the trail as it twisted and undulated around hills and into depressions--he
saw, far up the valley--and yet not so far, either--not more than two
miles--a horseman, riding slowly--away from him.

The horseman was the spy, of course. Harlan had no doubt that if he
lingered in the vicinity of the covert long enough he would discover the
place where the horse had been concealed. But that was not important, now
that he had discovered enough to satisfy himself that there had been a
spy--and so he rode on, smiling faintly, knowing that the rider was
headed into the valley--possibly to the outlaw rendezvous to appraise
Deveny and the others of his coming.

The t