See this show for the fine performances and inventive production design, not for its plodding, incredible plot. Director Barbara Gaines leaves the ending of Shakespeare’s “comedy” open–will the virtuous Isabella take vows as a novitiate or a wife?–offering modern audiences some hope that at least one woman will find happiness outside marriage. But Gaines’s decision can’t overshadow the frustration of seeing the spurned Mariana beg to wed the villainous Angelo, a pious hypocrite who attempts to assault Isabella’s honor. Among this production’s standouts are Jay Whittaker, who humanizes the stern Angelo, tormented by lust and self-loathing; Dana Green’s intelligent, passionately upright Isabella; and Sean Fortunato’s slippery lecher, Lucio. Felicia P. Fields’s Mistress Overdone and Kevin Gudahl’s Pompey bring verve and energy to the Viennese brothel scenes, enhanced by Christopher Akerlind’s lights; Virgil Johnson’s costumes brighten up Neil Patel’s austere set. Through 3/20: Tue 7:30 PM, Wed 1 and 7:30 PM, Thu 7:30 PM, Fri 8 PM, Sat 4 and 8:30 PM, Sun 3 PM. Wed 3/9, 7:30 PM only. No show Thu 2/24. No Tue show 2/15-3/15. Chicago Shakespeare Theater, Navy Pier, 800 E. Grand, 312-595-5600 (TTY 312-595-5699). $48-$65.