"Run within the beast-fires, Nat-ul," he cried; "Zor's mate is coming to his aid."

And sure enough, springing lightly across the sands came a fierce lioness, maned like her lord.

Now Dag's fellow warrior had sprung to his side, and from the camp were running the balance of the savage spearmen. Zor, rearing upon his hind feet, was striking at Dag who leaped nimbly from side to side, dodging the terrific blows of the mighty, taloned paws, and striking the beast's head repeatedly with his heavy ax.

The other warrior met the charge of the infuriated lioness with his spear. Straight into the broad breast ran the sharp point, the while the man clung tenaciously to the haft, whipped hither and thither as the beast reared and wheeled and struck at him with her claws.

Now Nu, the chief, and his fellows arrived upon the scene. A score of spears bristled from the bodies of Zor and his mate. Axes fell upon their heads, and Nu, the mighty, leaped upon Zor's back with only his stone knife. There he clung to the thick mane, driving the puny weapon time and again into back and side until at last the roaring, screaming beast rolled over upon its side to rise no more.

The lioness proved more tenacious of life than her lord, and though bristling with spears and cut to ribbons with the knives of her antagonists she charged into close quarters with a sudden rush that found one of the cave men a fraction of a second too slow. The strong claws raked him from neck to groin and as he fell the mighty jaws closed with a sickening crunch upon his skull.

At bay over her victim the lioness stood growling and threatening, while the wild warriors danced in a circle about her awaiting the chance to rush in and avenge their comrade.

Within the circle of fires Nat-ul replenished the blaze, keeping the whole scene brilliantly lighted for the warriors. That she had stumbled upon men of her own tribe so unexpectedly seemed little short of miraculous. She could scarce wait for the battle with the lions to be concluded, so urgent was the business that filled her thoughts.

But at last Zor's savage mate lay dead, and as Nu, the chief, returned to the camp Nat-ul leaped forward to meet him.

"Quick!" she cried. "They are killing Nu, thy son," and she pointed toward the south in the direction of the glare that was now plainly visible through the darkness.