In N.C. Wyeth's "Octave Plunged," a man fights a raging current, viewed from below the falls over which his hewn raft is about to plummet. He's a lone traveler pitched heroically against the elements. The painting leads the Kemper Museum of Contemporary Art's exhibition Wyeth: Three Generations of Artistry, a retrospective inspired in part by Andrew Wyeth's death in January. The painting's exciting subject matter and the visual drama reveal the artist himself: an adventurer whose artistic passions drove him into the American West...