Robynne M. Gravenhorst's imaginative, sensual, nightmarish dance-opera piece returns for four midnight shows at the Mercury Theater. Through pantomime, song, and carefully layered choreography, the Anatomical Theatre traces the obsessive journey toward unholy knowledge by a fictional 19th-century vivisectionist, Charlotte DeVoux, who's supplied illegally with corpses by grave robbers (known in France as les corbeaux, "the crows"). When I saw this piece last spring during its brief run, I felt I'd been taught an entirely new kind of fear--a visceral fear of scientific absolutism, which terrorizes both vivisectionist and audience in the forms of a chorus of flayed corpses and a mincing, clownish crow. This is a brilliantly executed contemporary morality tale about the apocalyptic effects of knowledge that rivals Edgar Allan Poe's grimmest psychological horrors. Mercury Theater, 3745 N. Southport, 773-325-1700. October 25-November 2: Friday-Saturdays, midnight. $15.