A play about racism and wrongful application of the death penalty may not be the most upbeat way to spend a summer evening on Lake Michigan, but A Lesson Before Dying is worth it. Originally performed as part of Steppenwolf Theatre Company's Arts Exchange program, Romulus Linney's fleet stage adaptation retains the power, humor, and period flavor of Ernest J. Gaines's award-winning novel, set in 1940s Louisiana. In this intimate drama, a schoolteacher frustrated by the futility of his life reluctantly helps an innocent black man sentenced to death by a jury of white men. Director Edward Sobel has restaged the show for Theater on the Lake's thrust stage, and performers will wear body mikes. But the entire original cast is returning for this remount: Robert Breuler's gruffly antagonistic sheriff, Sean Cooper's sympathetic jailer, Eltony Williams's schoolteacher, Bakesta King as his good-hearted girlfriend, and Tory O. Davis as the condemned Jefferson--a character who becomes a man right before our eyes. Theater on the Lake, Fullerton and Lake Shore Dr., 312-742-7994. Opens Wednesday, July 21, 7:30 PM. Through July 25: Thursday-Saturday, 7:30 PM; Sunday, 6:30 PM. $15.