A man and a woman who seems to be anything but a thug, enters a jewlery store to steal a watch, and kill the store owner. The reason seems to just be on a whim. Mary gets to Blackie’s apartment to find a strange woman who claims to be a former high school classmate. Mary doesn’t remember her, but the woman fills her in. After the wierd encounter, we find out why it took place. It’s the woman from the opening scene, and her male accomplice talks with her about setting up Boston Blackie to take the fall for the jewelry store job.
As Mary is telling Blackie about her odd events, Farraday barges in to confront Blackie for the latest murder on the streets, which is yet another set up for Blackie by our mystery thugs. Blackie attends the funeral and talks to the mom of the latest victim, and assures her that he’ll find the killer. Blackie has a handle on the case, a bad guy who he put behind bars has gotten out, and getting some revenge. In an odd twist of fact checking, it is uncovered that the woman accomplice actually is a girl who went to high school with Mary.
Blackie once again has to fill in Farraday about the finer points of the clues, and look past the obvious evidence on Blackie. Given a little time, Farraday lets Blackie do his work, and close in on the bad guys. To try to keep Blackie off balance, they plan to kidnap Mary to use as a shield as they make their get away.
Using the cops as his safety net, and being a half step behind the crooks, Blackie sets out to catch up to them before harm comes to Mary. Through his amazing tracking ability, Blackie rushes in just in time.