The Phantom Creeps is a 1939 serial about a mad scientist who attempts to rule the world by creating various elaborate inventions. In a dramatic fashion, foreign agents and G-Men try to seize the inventions for themselves.
Dr. Bernard Adrian is a kindly scientist who seeks to cure a young woman's polio. All he needs is spinal fluid from a human to complete the formula for his experimental serum. Meanwhile, a vicious circus ape has broken out of its cage, and is terrorizing the townspeople.