I've looked and looked, but can't find a story 'I know I saved!" Anyway, stories about a young man who's village is attacked while he's hunting, comes back and hides with a girl under a waterfall. They then, with the help of a few savors, defend a small ledge above the waterfall from the invaders, eventually driving them off. They then build a new tribe with him as chief. Anyone know the title and anther?