Hilltop stood to the front, between two rocks some few yards apart, over which bubbled the shallow creek, and between which was the main upward entrance to the valley. He stood upon a rock almost as flat as if some expert engineer of ages later had planed its surface and then adjusted it to a level, leaving the shallow waters tumbling all about it. The rock out-jutted somewhat on the slope and there must necessarily be some little climb to face the aged defender. On either side was a stretch of down-running, gradually-sloping waterfall, full of great boulders, embarrassing any straight rush of a group together, but, between and upward, sprang swart men, and facing them on either side of old Hilltop beyond the rocks were the remainder of the mass of cave men upon whom he depended for making good the defense of the whole barrier. Beside him, in the center of the battle, were the two creatures in the world upon whom he could most depend, his stalwart and splendid sons, Strong-Arm and Branch. With them, as gallant if not as strong as his great brother, stood braced the eager Bark. They were ready, these young men, but, as it chanced, there could be, at the beginning of the strong clamber of the foe, only one man to first meet them. All were behind this man at the front, for the flat rock came to something like a point. He stood there, hairy and bare except for the skin about his hips, and with only an ax in his hand, but this did not matter so much as it might have done, for only axes were borne by the up-clambering assailants. The throwing of an ax was a little matter to the sharp-eyed and flexile-muscled cave men. Who could not dodge an ax was better out of the way and out of the world. A meeting such as this impending must be a matter only of close personal encounter and fencing with arm and wooden handle and flint-head of edge and weight.