This KC Rep staging of the Mark Twain staple benefited from swiftly shifting scenes on a fluid, minimal set, which took as its central focus that famous, due-for-a-whitewash fence. Here, the massive set piece worked both to separate action and to symbolically divide the worlds of children and adults. We wondered, though: How would that dominating piece of scenery get its notorious painting? Robert Wierzel had the answer. His mood-setting, attention-directing lights were inventively incorporated in a big video display. Before our eyes, the slats changed color as Tom's friends did the dirty work — or appeared to — in a virtual picket-fence makeover. It was an inventive technological flourish that added to the show's sense of wonderment — and impressed us nontechies.