e
sprang sideways and bent to lay down his instrument, with the
instinctive carefulness of an old railroad surveyor. A swift rush
towards Ashton barely saved him from the second bullet that came
pinging down from the hill crest. It burned across the back of his
shoulder.

Heedless of the blood spurting from the wound in the side of Ashton's
head, Blake snatched up the automatic rifle and fired at a point
between two knobs of rock on the hill crest. Promptly a hat appeared,
then an arm and a rifle. It might have been expected that a bullet
would have instantly followed; yet the assassin was strangely
deliberate about getting his aim. Blake did not wait for him. He began
to fire as fast as the automatic ejector and reloader set the rifle
trigger. Three bullets sped up at the assassin before he had time to
drop back out of sight.

Blake started up the hillside, his pale eyes like white-hot steel. He
was in a fury, but it was the cold fury of a man too courageous for
reckless bravado. He went up the hill as an Apache would have charged,
dodging from cover to cover and, wherever possible, keeping in line
with a rock or tree in his successive rushes. At every brief stop he
scanned the ridge crest for a sign of his enemy. But the assassin did
not show himself. For all that Blake could tell, he might be waiting
for a sure shot, or he might be lying with a bullet through his
brain.

To avoid suicidal exposure, the engineer was compelled to veer off to
the right in his ascent. He reached the ridge crest without a shot
having been fired at him. Leaping suddenly to his feet, he scrambled
up to the flat top of a high crag, from which he could peer down upon
the others. The natural embrazure from which the assassin had fired
was exposed to his view; but the place was empty. He looked cautiously
about at the many huge bowlders behind which a hundred men might have
been crouching unseen by him, advantageous as was his position. To
flush the assassin would require a bold rush over and around the
rocks.

Blake set his powerful jaw and gathered himself together for the leap
down from his crag. At that moment his alert eye caught a glimpse of a
swiftly moving object on the mesa at the foot of the far side of the
hill. It was a horse and rider racing out of sight around the bend of
a ridge point.

Blake whipped the rifle to his shoulder. But the cowardly fugitive had
disappeared. He lowered the rifle and started back down the hill