The Kane family had always believed that some moments arrive unannounced—like a sudden breakaway or an unexpected wave on calm water.

It was a crisp October afternoon in Evergreen Hollow, the leaves at their fiery peak, the pond reflecting a sky streaked with clouds. The house was quiet for once—the grandchildren scattered to college games and practices, the great-grandchildren with sitters.

Only the original generation remained: Rowan and Holly, Lily and Nathan, Everett and ...