Down on the waterfront a mobster runs the dock, and people who don’t have his approval end up dead. Blackie had been planning a cruise, but as Farraday sees him off, word of the murder comes in, and Blackie changes his plans.
The mobster, named Palmer, has a protection racket where dock hands pay him protection, or end up dead. The cops have the evidence they need to prove the recent accident was murder, and start to move in. Meanwhile, Blackie moves in in his own way to put pressure on the mob boss. As the gangsters talk openly about the racket they have going on, Blackie barges in, only to get a thump on the head.
Blackie touches base with Farraday to compare notes, and trade sarcastic wisecracks. Are these guys friends, enemies, or just an old married couple?
Blackie and Farraday join forces, and discover their man, Palmer, is dead. Though Farraday is stumped, Blackie seems to have a clue to go on, and begins to follow up on it. Armed with more clues, Boston Blackie phones Farraday with a plan to catch the new racketeer on the dock.
Blackie sets himself up for danger, with the hopes that Farraday will be his safety net. Wow, what a trusting soul. As straight forward as the plan seems on the surface, there’s still a mystery to solve, and only Blackie realizes who the real killer is. In the end, Blackie manages to put a stop to the racket, and bring down the killer as well.