"Clothes make the man," Mark Twain wrote. "Naked people have little or no influence in society." In this one-man show drawn from little-known stories and unpublished anecdotes by and about the great humorist, Richard Henzel shuffles and struts in a dapper white suit, which he calls "the uniform of the American Association of Purity and Perfection," a facade of white Christian righteousness worn to mask the worst in human nature--greed, envy, intolerance, and the ability to ignore the sufferings of others. Twain's special genius was his ability to present himself (or a surrogate such as Huckleberry Finn) as a satirically instructive model of mankind's failings, his folksy congeniality rubbing raw against the darkness of his content. Henzel's convincing portrayal of the author-lecturer at 71 is often disarming (warm, witty recollections of teenage high jinks and the comically complicated courtship of his wife Livy) and alarming (a perplexed account of feeling guilt after killing an enemy soldier during the Civil War, which leads into a tale about a fellow who literally murders his own conscience). The man in the white suit isn't just Mark Twain; he's every one of us who ever stifled shame as we turned away from a homeless panhandler or squelched misgivings as we celebrated the ruin of a rival. When Henzel's Twain entertains us by blowing soap bubbles full of cigar smoke, we're charmed by the quirkiness of an old man's amusements; but the dark cloud inside the gleaming bubble makes a memorable metaphor for Twain's work and the world it reflects. Body Politic Theatre, through February 16 (2261 N. Lincoln, 871-3000). Wednesdays-Fridays, 7:30 PM; Saturdays, 5 and 9 PM; Sundays, 2:30 PM. $12-$15.