appeared to be grimly and conscientiously concerned over his task,
and he was worried about the outcome. He must get his car beyond that
narrow cut. If it jumped the track or ran into an obstruction, or if
the Sioux spied him in time, then his work would not be well done. He
welcomed the gathering momentum, yet was fearful of the curve he saw a
long distance ahead. When he reached that he would be going at a high
rate of speed--too fast to take the curve safely.

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.