He raised his voice in a wild howl of challenge. For a moment there was silence. Then from the ravine came a hoarse rumbling bellow. An enormous male made his appearance, his mane and beard bristling with rage. He darted his eyes hither and thither, seeking the source of the challenge. Again a hoarse roar came from his broad, thick lips. As it rose to a crescendo, Anak hurled his spear. His aim was true. The point struck the Neanderthaler at the junction of his neck and shoulder. As it struck, the haft flew from the spear and bounded down the slope. The first point made only a surface wound. The apeman roared with pain and rage. Still he did not see his enemies. With careful aim, Invar launched his weapon. The stone-tipped spear struck the giant's groin, but the haft broke and the head was barely buried in the flesh. The Neanderthaler pricked up his pointed, lobeless ears, and located the source of the shout. By bending back his torso, he looked upward. With a roar of rage he started up the slope, a huge flint smiting-stone grasped in each hairy paw. Anak and Invar dashed up the slope ahead of him. The keenness of the Chief Hunter's powers of observation was attested by the fact that they easily increased their distance from their pursuer. As they ran, Invar's foot dislodged a boulder which thundered down the slope. The Neanderthaler did not see it coming until it was too late to dodge. The stone took him full in the chest and he rolled down the slope, a shower of smaller stones going with him. He smashed against a tree. With shouts of triumph, Anak and Invar bounded down the slope. The Neanderthaler was dying, his chest crushed in. Invar raised a spear and drove it at his heart. The weapon struck fair, but again the head of the spear came off the shaft. A sudden thought illuminated Anak's brain. "Esle!" he cried in rage. "She had our weapons last night!" * * * * * He studied the two spears remaining in his hand. Each of them had the hide lashing which bound the head to the haft cut through. The weapons were useless. Invar's face paled. From up the slope a roar assailed their ears. The female was rushing down at them, smiting-stones in hand. "Fly, Invar!" cried Anak. "Run up the slope and throw down stones at her. I will hold her for a moment." "Invar stays with his friend!" cried the boy stubbornly as he gripped his useless throwing-spear. "Run up the slope!" stormed Anak. "It is our only chance. Remember how the male died!" Slowly the idea penetrated Invar's brain. With a shout he dashed away. He circled the oncoming female and got above her. Anak hurled one of his crippled spears. It struck her full in the chest, but made only a flesh wound as the handle dropped away. The female roared with rage and hurled herself at the hunter. Anak leaped to one side and ran for dear life. The clumsy female checked her rush and turned after him. He rapidly gained on her. A shout from above reached him.