History
At the office of Mark Mason, private detective, Joan Holman comes to hire Mason for a case. Eavesdropping over the office intercom, Louise Grant overhears how Joan's fiancée Joe Brand has been accused of murdering Cecily Harding. Louise remarks how Joan is giving up her million dollar cosmetics business to marry Joe, who is an old high school sweetheart. She overhears the details of the case: although Joe is a police detective and a war hero he is the likely suspect. On the night in question Joan, was having dinner with Cecily and her business manager Van Glint when the fuse went out. When the power turned back on Cecily was stabbed to death and the killer had stolen her ruby pendant, and the last person in the room before the homicide squad investigated was Joe.
After work, Louise decides to get involved in the case as the Blonde Phantom. To this end, she decides to interview the other man who was present at the murder, Joan's publicity photographer Pietro. At Pietro's home, Van Glint is meeting with Pietro and chastising him for taking a photo as he was murdering Cecily. Pietro tells Van Glint that nobody saw him but then attempts to blackmail him as he has a photograph of Van Glint murdering Cecily. Not willing to bend to blackmail, Van Glint guns down Pietro just as the Blonde Phantom arrives at the door. When she rushes in she is knocked out from behind by Van Glint who flees the scene. Reviving shortly after, Blonde Phantom takes Pietro's camera and begins searching through his papers when Joe Brand arrives. When Blonde Phantom presses him about an IOU she just found, Joe admits that he had a gambling debt with Pietro and Van Glint that he was coming to see them about to ask him not to mention it during the police investigation. Blonde Phantom has Joe sit down and explain his perspective of the night of Cecily's murder. He explains that on that night Cecily and Joan were discussing how Cecily would be taking over management of the cosmetics company when Joan gets married when the lights suddenly went out and that after Cecily was murdered it was his mistake to leave the room even if he was a police detective.
When the police arrive at the scene of Peitro's death, Blonde Phantom slips away and places a call to Mark Mason and asks him to have Joan meet her at Joan's office. There, the Blonde Phantom has Joan let her look through the company records where she finds proof that Van Glint had been embezzling money from the company. Van Glint suddenly arrives and holds them at gun point, explaining that he killed Cecily and framed Joe so that Joan wouldn't get married and he could keep up his lucrative embezzlement scheme without anyone's notice. Before they can shoot them, the Blonde Phantom pulls out her compact and uses a nearby fan to blow the powder into Van Glint's face, temporarily blinding him. Blonde Phantom then knocks him out just as Mark arrives with the police. Explaining the whole plot to them, Van Glint is arrested. Mark explains that they came when they found a photo negative of Van Glint murdering Cecily while searching Pietro's apartment.[1]