Black prisoner Ray Stone clashes, because of his social and political commitment, with corrupt warden Tompkins. When shortly after Ray lies apparently beaten to death, in the isolation cell, rude attendant Bull Stewart is considered the culprit, since he was the only one who had access to the cell. Quincy is instructed to perform the autopsy on the corpse. When the indignant cell mates cause a riot and take Quincy and Sam as hostages and then they go to lynch Bull Stewart right away, the pathologist must persuade the angry mob to remain still and wait for the results of the investigation. Should the cause of death point to a murder, Stewart will be released by the prisoners. They let Quincy go. Nevertheless, his assistant Sam stays as a hostage in the hands of the distrustful prisoners.