Summer — Laurence E. Dahners

The third book in the Bonesetter series, a pre-historical account of Pell, a boy in a primitive society who learns to "set bones." In this third story he's become the de facto leader of the Cold Springs tribe, though he still resists the mantle. The tale follows his invention of such things as the spear thrower, chimney and the beginnings of agriculture. Things that will markedly improve the lives of his fellow humans. He and Gia mate and, in hopes of finding more lost members of Gia's former tribe, set out to travel the great river to the sea. Despite the awe his ideas engender in those around him, he remains humble and commits himself to helping those in need -- even the ones he doesn't like.