On a golden afternoon behind their house, Jensina and her big brother Hawkwynd stood where the garden grass met the rushing Silver-Creek.

Hawkwynd, wearing a coat of many pockets and a tall paper crown, declared they were the Great Giant Builders of the Valley.

They had spent all morning together, sharing a bowl of tart berries and a big idea: they would protect the tiny, quiet world at the water's edge from the wild, splashing currents that threatened to wash everything away.