A gang of thugs meet to develop their evil plans, but how does Boston Blackie fit in? As Blackie and Mary enjoy a quiet moments, Shorty rushes in to spill the beans about a frame up that will lay the blame at Blackie’s feet. Can Black give a heads up to Farraday? Will the cop believe him? Is there an alibi that Blackie can arm himself with? All Blackie’s friends are frantic, and offer their ideas to keep him safe, but the ever unflappable Blackie turns down all their ideas. Instead, he goes to face the gang ringleader.
The heist of the Wentworth Diamond goes down, and the murder of the security guards, all designed to trap Blackie in a tough spot. Has Blackie managed to protect himself? Farraday persists in blaming Blackie, but will need convincing. Blackie leads Farraday through each step of the plan to both set himself free, and expose the real thief and killer.
How did he manage to turn the tables? As elaborate as the plan was against him, Blackie tells how he counteracted the frame up, and hands over his enemy to the cops.