Mild-mannered Everett P. Digberry is found wandering in a cemetery by police and arrested for loitering. Digberry protests, claiming he was supposed to meet a man known only as the Black Panther, who had been blackmailing him. But the paw print on the blackmail note belongs to Blackberry's own cat. Then, opera singer Nina Politza (Rozan) is found murdered, and Digberry, her lover, is the prime suspect. However, commissioner Thatcher Colt (Blackmer) doubts Digberry committed the crime, due to a large number of other suspects with better motives for murder. Rival wigmaker Samuel Wilkins is killed and the murder weapon planted in Digberry's apartment. Commissioner Colt must clear Digberry's name and find the real murderer before someone else is killed.