When a prizefighter is gunned down during a match, the initial speculation is that he was punished for refusing to take a dive. But Joe Mannix, who happened to attend the match, speculates that the bullet may have been meant for someone in the audience -- and a review of the fight film suggests that the real target was Mannix himself. This is reinforced when there is another attempt on Mannix' life -- but the evidence begins to point to someone whom Mannix believes couldn't possibly have tried to commit the murder.
—aldanoli