Lon plays Dan, a man who has an electrical act in a carnival who is the only person to survive a bus accident. He meets up with two doctors, Dr. Lawrence and Dr. Rigas.
When Dr. Lawrence is out of town Dr. Rigas (Lionel Atwill) uses his experiments to turn an into an electrical monster that kills Dr. Lawrence. Dan is sentenced to death in the electric chair, and sure enough he doesn't die, but becomes a super charged monster.
This is a very fun Universal monster romp that any horror fan will enjoy. The cast is top notch as usual, and seeing Chaney as an electrical man is always cool. Samuel Hinds is the kindly Dr. Lawrence and Anne Nagle is his daughter.
See this film and spend a very enjoyable hour.