Dr. Carl Decker runs an optometrist shop on the San Francisco waterfront, but he also doubles as a Nazi spy for the Bay area. Decker is robbed of his code book, which also contains the names of all the enemy agents in the area. Decker and Marlow, another spy who just arrived in San Francisco to have his orders decoded by Decker, go off in search of the present owner of the book, who is also one of the Nazi spies operating on the west coast. Marlow, however, has a nasty streak to him, blackmailing the owner of a boarding house owner, Mrs. Hausner with impending threats to her family still living in Germany, and not being shy about using his gun when the situation arises. Marlow eventually shoots another Nazi collaborator Kramer, who is running out and Marlow believes will rat on him and Decker, and the crime is pinned on Jerry Donovan, the fiancé of Mrs. Hauser's daughter, Freda. Eventually Marlow has to prevent the Maxwell murder from coming back to him, while avoiding capture at the same time. Pretty good war time espionage flick with good performances from Carradine and Naish. The rest of the cast is standard for a PRC production. The climax of the film is really a drawback, lacking much excitement and seemingly rushed. Rating, 7.