Johnny Broderick, arson squad investigator, and his assistant, Ben Howard,, investigate a warehouse fire and find evidence of arson. Lawyer William Yarbo is behind the series of incendiary fires that have been plaguing the city. Keely Hariss, an actress, inherited the warehouse from her father. Yabro calls on her and says that he and her father had heavily insured the building and planned to burn it and collect, and also tells her she must accept half of the insurance money or he will see that she is blamed for the arson. "Pop" Bergen, the father of Marily Bergen, is the torch man hired by Yarbo, and he perishes in one of the conflagrations. Yarbo learns that Keely is cooperating with Broderick and he enters the movie studio where she is working, determined to kill her.