They moved forward at a walk and reached a higher level, across which the night wind swept, bearing a touch of cold in its breath as though coming from the snow-capped mountains to the west.  There was renewed life in this invigorating air, and Murphy spurred forward, his companion pressing steadily after.  They were but two flitting shadows amid that vast desolation of plain and mountain, their horses’ hoofs barely audible.  What imaginings of evil, what visions of the past, may have filled the half-crazed brain of the leading horseman is unknowable.  He rode steadily against the black night wall, as though unconscious of his actions, yet forgetting no trick, no skill of the plains.  But the equally silent man behind clung to him like a shadow of doom, watching his slightest motion—­a Nemesis that would never let go.

When the first signs of returning day appeared in the east, the two left their horses in a narrow canyon, and crept to the summit of a ridge.  Below lay the broad valley of the Powder.  Slowly the misty light strengthened into gray, and became faintly tinged with crimson, while the green and brown tints deepened beneath the advancing light, which ever revealed new clefts in the distant hills.  Amid those more northern bluffs a thin spiral of blue smoke was ascending.  Undoubtedly it was some distant Indian signal, and the wary old plainsman watched it as if fascinated.  But the younger man lay quietly regarding him, a drawn revolver in his hand.  Then Murphy turned his head, and looked back into the other’s face.

CHAPTER IV

THE VERGE OF CONFESSION

Murphy uttered one sputtering cry of surprise, flinging his hand instinctively to his hip, but attempted no more.  Hampton’s ready weapon was thrusting its muzzle into the astounded face, and the gray eyes gleaming along the polished barrel held the fellow motionless.

“Hands up!  Not a move, Murphy!  I have the drop!” The voice was low, but stern, and the old frontiersman obeyed mechanically, although his seamed face was fairly distorted with rage.

“You!  Damn you!—­I thought I knew—­the voice.”

“Yes, I am here all right.  Rather odd place for us to meet, isn’t it?  But, you see, you’ve had the advantage all these years; you knew whom you were running away from, while I was compelled to plod along in the dark.  But I ’ve caught up just the same, if it has been a long race.”

“What do ye—­want me fer?” The look in the face was cunning.

“Hold your hands quiet—­higher, you fool!  That’s it.  Now, don’t play with me.  I honestly didn ’t know for certain I did want you, Murphy, when I first started out on this trip.  I merely suspected that I might, from some things I had been told.  When somebody took the liberty of slashing at my back in a poker-room at Glencaid, and drove the knife into Slavin by mistake, I chanced to catch a glimpse of