He was reaching for his deadly weapon, so was the black, or to get himself into a better position for assault.

And as Nic with throbbing breast drew slowly nearer, never once taking his eyes from those of his foe, the knitted brows and shining black face seemed to approach.
But he knew it was only an optical illusion caused by the intense strain upon his eyes; and feeling that quick action was necessary, he made a sudden spring to his right and grasped the gun, with which he leaped to his feet, just as the black also bounded up with a long, quivering spear in his hand, while there, plainly seen in the narrow band about his waist, were the boomerang and club.
Click went Nic's gun trigger, as a thrill of confidence ran through him, and, holding the piece at the ready, he presented it at the black's breast.
At this the man made a bound backward, and throwing himself into an attitude, he levelled his spear, as if about to hurl it and pierce Nic through.
"I wish I knew nigger," thought Nic, getting more confident; "I'd tell him if he'd go away I would not fire." But no word was spoken on either side, white and black standing motionless in their attitudes of menace, eye fixed on eye, as if each were ready to shoot or hurl spear at the slightest movement made by the other.
The situation at last became so irksome that Nic could bear it no longer, and in a hoarse voice he cried: "Now then, be off, and I won't shoot." To his surprise the black shouldered his spear, and then obeyed a sign Nic made with the barrel of his gun, turning round and beginning to march away, slowly followed by the boy, who felt that if driven to extremities he could easily hit the broad, shiny back before him, with the muscles playing elastically at every step the man took.
"He understood the sign I made," thought Nic, who determined to keep near the black for fear of treachery, as the man strode on in and out among the trees, while a fresh idea now struck Nic.

Suppose the man was going on to join his companions who had cooeyed to him.

It was like walking into additional danger.

Still the boy did not flinch, for fear of receiving a spear in the back if he turned away.
But he was master for the moment; and growing more and more confident, he strode on behind the black, heedless of the direction in which they went, and leaving the end of the case to fate.