In this entry in the "Boston Blackie" series, the reformed crook meets his former lover who tells him that her father has just been freed from prison and that he is heading out to a safe deposit box where he hid a sack of diamonds. The good daughter wants her father to return the rocks and reform and wants Blackie to help him. Unfortunately, the father is murded en route to the bank and the hapless detective is arrested for the crime. Following his escape, Blackie learns that the girl has been kidnapped by gangsters who want her to reveal the location of the valuable box. There is a major showdown in a local nightclub when Blackie bursts in on the mob. In the end, he stops the gang, saves the girl, and overcomes temptation and returns the jewels. ~ Sandra Brennan, All Movie Guide