A little dimness came to Casey’s eyes.  Years of hot sun and dust and desert wind had not made his eyes any stronger.  The low gray walls, the white bleached rocks, the shallow stream of water, the fringe of brush, and the long narrowing track—­all were momentarily indistinct in his sight.  His breast seemed weighted.  Over and over in his mind revolved the several possibilities that awaited him at the cut, and every rod of the distance now added to his worry.  It grew to be dread.  Chances were against him.  The thing intrusted to him was not in his control.  Casey resented this.  He had never failed at a job.  The U. P. R. had to be built—­and who could tell?—­if the chief engineer and all his staff and the directors of the road were massacred by the Sioux, perhaps that might be a last and crowning catastrophe.

Casey had his first cold thrill.  And his nerves tightened for the crisis, while his horny hands gripped on the brake.  The car was running wild, with a curve just ahead.  It made an unearthly clatter.  The Indians would hear that.  But they would have to be swift, if he stayed on the track.  Almost before he realized it the car lurched at the bend.  Casey felt the off-side wheels leave the rail, heard the scream of the inside wheels grinding hard.  But for his grip on the wheel he would have been thrown.  The wind whistled in his ears.  With a sudden lurch the car seemed to rise.  Casey thought it had jumped the track.  But it banged back, righted itself, rounded the curve.

Here the gully widened—­sent off branches.  Casey saw hundreds of horses—­but not an Indian.  He rolled swiftly on, crossed a bridge, and saw more horses.  His grim anticipation became a reality.  The Sioux were in the ambush.  What depended on him and his luck!  Casey’s red cheek blanched, but it was not with fear for himself.  Not yet on this ride had he entertained one thought concerning his own personal relation to its fragile possibilities.

To know the Sioux were there made a tremendous difference.  A dark and terrible sternness actuated Casey.  He projected his soul into that clattering car of iron and wood.  And it was certain he prayed.  His hair stood straight up.  There! the narrow cut in the hill! the curve of the track!  He was pounding at it.  The wheels shrieked.  Looking up, he saw only the rocks and gray patches of brush and the bare streak of earth.  No Indian showed.

His gaze strained to find an obstruction on the track.  The car rode the curve on two wheels.  It seemed alive.  It entered the cut with hollow, screeching roar.  The shade of the narrow place was gloomy.  Here!  It must happen!  Casey’s heart never lifted its ponderous weight.  Then, shooting round the curve, he saw an open track and bright sunlight beyond.