"Health is an illusion," crows Dr. Knock, who believes that everyone is a patient who just doesn't know it yet. "We are all ill." This quack storms into a French hamlet and takes its healthy (and surprisingly wealthy) residents firmly in hand, cowing them through his bluster and confidence until he's created a tidy cult of hypochondria. Though the idea that the medical establishment wants us to be sick is an interesting one, Richard Hesler's clumsy adaptation and direction of Jules Romains' 1923 French farce lacks bite, style, and impact. The ensemble members play their French parts with generic British accents and can't fill out the thin characters, which are no more than a collection of types: a snooty grande dame, a truculent peasant, a windbag rival doctor. This production is DOA. Through 3/27: Thu-Sat 8 PM, Sun 3 PM. City Lit Theater Company, Edgewater Presbyterian Church, 1020 W. Bryn Mawr, 773-293-3682. $18-$25.