On the eve of his marriage to waitress Mary Roberts, taxi driver "Brick" Tennant is questioned as a murder suspect along with 120 other drivers, because a taxi served as the getaway car in a theater robbery in which a man was killed. When one of the witnesses swears that Brick and his hapless friend, Joe Linden, were the killers, the district attorney, eager for a conviction, brings the taxi drivers to trial even though Brick and Mary were in a church when the robbery took place. Although innocent, Brick and Joe are found guilty and sentenced to die in the electric chair. Mary, however, refuses to give up hope, and when she unearths a bullet from another robbery that was shot from the murder weapon, she convinces Lieutenant Everett of the police department that the wrong men have been convicted. After the district attorney refuses a stay of execution, Everett, now suspended from the force, joins Mary in her search for the high-speed cab that was driven in the hold-up. As the time of his execution approaches, Brick is transformed from an idealistic youth into a man whose faith in the system has been shattered. On the day of the execution, Mary and Everett finally find the cab, which leads them to the real murderers. The governor then pardons Brick, but although his life has been spared, his faith can never be repaired.