The natural course of action for one in the officer’s situation was to peer gradually round the edge of the rock to ascertain where his enemy was, but no man, after second thought, would attempt anything of that nature, for, it will be seen, that it was only taking the place of the hat on the end of the gun barrel. The watchful Apache was certain to detect the insidious advance, and, before the eyes came into view, would send a bullet through the brain of the daring white man.

Accordingly Lieutenant Decker adopted the opposite course. He darted his head forward, gaining one glance along the end of the rock, and withdrawing again, before the most alert enemy could fire. It was the right course under the circumstances and proved effectual.

The moonlight struck that portion of the boulder with full effect, there being not even a ribbon of shadow, and, in full view was the Apache, advancing on hands and knees, his hideous face half-hidden by the strands of black hair which dangled about his shoulders and in front of his chest and features.

Could Decker have known this a moment before, he would have discharged his revolver at the instant of catching his glance, but to have known it was to possess a knowledge that was impossible.

The puzzling question with him was whether the warrior had seen him. He must be depending more on his sense of hearing than on sight, and it would seem that there was reason to believe he had not caught that shadowy thrusting forward and withdrawal of the head. If such were not the fact, he must be unaware of the exact location of the white man, who had only to repeat the maneuver, accompanying it by an instant discharge of his revolver.

But, suppose he had observed the shadowy movement—ay, there was the rub.

If he had failed to see it, he would continue his advance, and continuing it, must disclose some part of himself at the corner of the boulder. Accordingly, the lieutenant partly straightened up, sitting on his heels, weapon grasped, and eyes and ears wide open.

But the minutes passed and nothing was developed. It was impossible to decide what had been done or what should be the next step. Since, however, the former strategy had brought him knowledge and no harm, Decker now repeated it, holding his weapon, so that if the Apache were in his old position he could reach him with a bullet.

It was like a man darting his head through a trap door, and with one instant, all-embracing sweep of his vision, dropping out of sight before any observer could do more than recognize him.