Chicago police detective Dicky Cobb turns in some crooked cops and finds himself persona non grata in the department. He is reassigned as an investigator for assistant D.A. Tess Kaufman, partly due to the fact that she is deaf and he can sign. Tess works for District Attorney Arthur Gold, a slick opportunist. Dicky investigates her cases, with the frequent help of Detective Earl Gaddis, a chain-smoking cop who is the only one on the force Dicky still gets along with.